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1.
PLoS One ; 19(3): e0299900, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38427681

RESUMEN

Eusocial insects such as termites, ants, bees, and wasps exhibit a reproductive division of labor. The developmental regulation of reproductive organ (ovaries and testes) is crucial for distinguishing between reproductive and sterile castes. The development of reproductive organ in insects is regulated by sex-determination pathways. The sex determination gene Doublesex (Dsx), encoding transcription factors, plays an important role in this pathway. Therefore, clarifying the function of Dsx in the developmental regulation of sexual traits is important to understand the social evolution of eusocial insects. However, no studies have reported the function of Dsx in hemimetabolous eusocial group termites. In this study, we searched for binding sites and candidate target genes of Dsx in species with available genome information as the first step in clarifying the function of Dsx in termites. First, we focused on the Reticulitermes speratus genome and identified 101 candidate target genes of Dsx. Using a similar method, we obtained 112, 39, and 76 candidate Dsx target genes in Reticulitermes lucifugus, Coptotermes formosanus, and Macrotermes natalensis, respectively. Second, we compared the candidate Dsx target genes between species and identified 37 common genes between R. speratus and R. lucifugus. These included several genes probably involved in spermatogenesis and longevity. However, only a few common target genes were identified between R. speratus and the other two species. Finally, Dsx dsRNA injection resulted in the differential expression of several target genes, including piwi-like protein and B-box type zinc finger protein ncl-1 in R. speratus. These results provide valuable resource data for future functional analyses of Dsx in termites.


Asunto(s)
Hormigas , Isópteros , Masculino , Animales , Isópteros/genética , Isópteros/metabolismo , Procesos de Determinación del Sexo/genética
2.
Sci Rep ; 13(1): 16091, 2023 Oct 12.
Artículo en Inglés | MEDLINE | ID: mdl-37828043

RESUMEN

Extensive air showers induced from high-energy cosmic rays provide a window into understanding the most energetic phenomena in the universe. We present a new method for observing these showers using the silicon imaging detector Subaru Hyper Suprime-Cam (HSC). This method has the advantage of being able to measure individual secondary particles. When paired with a surface detector array, silicon imaging detectors like Subaru HSC will be useful for studying the properties of extensive air showers in detail. The following report outlines the first results of observing extensive air showers with Subaru HSC. The potential for reconstructing the incident direction of primary cosmic rays is demonstrated and possible interdisciplinary applications are discussed.

3.
Cureus ; 15(4): e38128, 2023 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-37252485

RESUMEN

Background No study has evaluated whether the macroscopic appearance or histological features of the posterior cruciate ligament (PCL) affect the in vivo PCL function in cruciate-retaining (CR) total knee arthroplasty (TKA). The aim of this study is to elucidate the correlation between intraoperative gross appearances of the PCL and clinical parameters, their corresponding histological features, and the in vivo function. Methods The intraoperative gross appearances of the PCLs were evaluated; we also examined their correlations with clinical parameters, corresponding histological features, and the in vivo function in CR-TKA. Results There were significant correlations between intraoperative gross appearances of the PCL and that of the anterior cruciate ligament, the preoperative knee flexion angle, and the intercondylar notch stenosis. There was a significant correlation between the intraoperative gross appearance in the middle part and the corresponding histological features. However, there was no significant correlation between the intraoperative gross appearance or histological features and the PCL tension, amount of rollback, and maximum knee flexion angle. Conclusions The intraoperative gross appearance of the PCL correlated with clinical parameters. Also, there was a significant correlation between the intraoperative gross appearance in the middle part and the corresponding histological features; however, there was no correlation between the intraoperative gross appearance or histological features and the in vivo function.

4.
Intern Med ; 62(13): 1915-1920, 2023 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-36418091

RESUMEN

Objective Both renal hypouricemia (RHU) and gout are associated with renal dysfunction and urolithiasis. The difference in renal complications associated with RHU and gout, however, has not been studied. We characterized the urate metabolism and complications of patients with RHU and compared them with patients with gout. Methods Eighteen patients with RHU who had a serum uric acid (SUA) level <2 mg/dL (10 men and 8 women), 44 patients with gout (44 men) and 16 normouricemic patients (4 men and 12 women) were included. The blood and urinary biochemical data were evaluated. A genetic analysis of uric acid transporter 1 (URAT1) was also conducted in 15 cases with RHU. Results The SUA level of RHU was 0.9±0.5/mg/dL, and the Uur/Ucr and Cur/Ccr were 0.56±0.14% and 45.7±18.0%, respectively. A genetic analysis of URAT1 in 15 RHU patients showed that 13 harbored a URAT1 gene mutation, whereas 2 harbored the wild-type gene. The SUA level was significantly lower in RHU patients (n=11) than in either gout patients (n=44) or normouricemic patients (n=16). This reduction was accompanied by the elevation of Cua/Ccr. Urinary beta 2-microglobulin levels were higher in RHU patients than in gout or normouricemia patients. Cua/Ccr correlated with normalized urinary beta 2-microglobulin levels. The prevalence of urolithiasis was 18.2% in RHU cases and 6.8% in gout cases. A homozygous URAT1 mutation was associated with urolithiasis. Conclusion Besides urolithiasis, RHU can be associated with tubular dysfunction, such as elevated urinary beta 2-microglobulin levels.


Asunto(s)
Gota , Cálculos Urinarios , Masculino , Humanos , Femenino , Ácido Úrico , Microglobulina beta-2 , Gota/complicaciones , Gota/genética , Cálculos Urinarios/complicaciones , Cálculos Urinarios/genética
5.
Phys Rev Lett ; 129(6): 061301, 2022 Aug 05.
Artículo en Inglés | MEDLINE | ID: mdl-36018664

RESUMEN

We report the first detection of the dark matter distribution around Lyman break galaxies (LBGs) at high redshift through the cosmic microwave background (CMB) lensing measurements with the public Planck PR3 κ map. The LBG sample consists of 1 473 106 objects with the median redshift of z∼4 that are identified in a total area of 305 deg^{2} observed by the Hyper Suprime-Cam Strategic Survey Program survey. After careful investigations of systematic uncertainties, such as contamination from foreground galaxies and cosmic infrared background, we obtain the significant detection of the CMB lensing signal at 5.1σ that is dominated by 2-halo term signals of the LBGs. Fitting a simple model consisting of the Navarro-Frenk-White profile and the linear-bias model, we obtain the typical halo mass of M_{h}=2.9_{-2.5}^{+9.5}×10^{11} h^{-1} M_{⊙}. Combining the CMB lensing and galaxy-galaxy clustering signals on the large scales, we demonstrate the first cosmological analysis at z∼4 that constrains (Ω_{m0},σ_{8}). We find that our constraint on σ_{8} is roughly consistent with the Planck cosmology, while this σ_{8} constraint is lower than the Planck cosmology over the 1σ level. This study opens up a new window for constraining cosmological parameters at high redshift by the combination of CMB and high-z galaxies, as well as studying the interplay between galaxy evolution and large-scale structure at such high redshift, by upcoming CMB and optical and near-infrared imaging surveys.

6.
Arthropod Struct Dev ; 69: 101169, 2022 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-35660224

RESUMEN

In a majority of ants, a newly mated queen independently founds a colony and claustrally raises her first brood without foraging outside the nest. During claustral independent colony foundation (ICF) in several ants, the esophagus of the founding queen expands and develops into a "thoracic crop," which is then filled with a liquid substrate for larval feeding. It has been suggested that these substrates are converted from the founding queen's body reserves (e.g., histolyzed flight muscles) or redistributed from a gastral crop. Here, we describe thoracic crop development in Lasius japonicus queens during claustral ICF. The foundresses claustrally feed their larvae from weeks 2-5 after ICF onset, and the first worker emerges at week 6. The development proceeds as follows: in week 0, the foundress' dorsal esophageal wall is pleated and thickened. Then, from weeks 2-5, the esophagus expands toward a dorsal space previously occupied by flight muscles, following flight muscle histolysis. Gastral crop expansion follows esophageal expansion. Thus, thoracic crop formation may be spatiotemporally coordinated with flight muscle histolysis in Lasius japonicus queens, and similar developmental regulations might be common in other claustral ICF ants.


Asunto(s)
Hormigas , Animales , Hormigas/fisiología , Femenino , Larva , Músculos , Reproducción/fisiología
7.
Intern Med ; 61(9): 1383-1386, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35491177

RESUMEN

Whether or not extremely low levels of serum uric acid (SUA) in xanthinuria are associated with impairment of the endothelial function and exercise-induced acute kidney injury (EIAKI) is unclear. A 59-year-old woman without EIAKI or urolithiasis had undetectable levels of UA in serum and urine and elevated levels of hypoxanthine and xanthine in urine. A genetic analysis revealed homozygous mutations in the XDH gene [c.1585 C>T (p. Gln529*)]. Flow-mediated dilation was within the normal range. This is the first report of a case with extremely low levels of SUA, xanthinuria with novel mutations of xanthine dehydrogenase (XDH) and a normal endothelial function.


Asunto(s)
Errores Innatos del Metabolismo , Xantina Deshidrogenasa , Femenino , Humanos , Errores Innatos del Metabolismo/genética , Persona de Mediana Edad , Mutación/genética , Ácido Úrico , Xantina Deshidrogenasa/deficiencia , Xantina Deshidrogenasa/genética
8.
Proc Natl Acad Sci U S A ; 119(3)2022 01 18.
Artículo en Inglés | MEDLINE | ID: mdl-35042774

RESUMEN

Termites are model social organisms characterized by a polyphenic caste system. Subterranean termites (Rhinotermitidae) are ecologically and economically important species, including acting as destructive pests. Rhinotermitidae occupies an important evolutionary position within the clade representing a transitional taxon between the higher (Termitidae) and lower (other families) termites. Here, we report the genome, transcriptome, and methylome of the Japanese subterranean termite Reticulitermes speratus Our analyses highlight the significance of gene duplication in social evolution in this termite. Gene duplication associated with caste-biased gene expression was prevalent in the R. speratus genome. The duplicated genes comprised diverse categories related to social functions, including lipocalins (chemical communication), cellulases (wood digestion and social interaction), lysozymes (social immunity), geranylgeranyl diphosphate synthase (social defense), and a novel class of termite lineage-specific genes with unknown functions. Paralogous genes were often observed in tandem in the genome, but their expression patterns were highly variable, exhibiting caste biases. Some of the assayed duplicated genes were expressed in caste-specific organs, such as the accessory glands of the queen ovary and the frontal glands of soldier heads. We propose that gene duplication facilitates social evolution through regulatory diversification, leading to caste-biased expression and subfunctionalization and/or neofunctionalization conferring caste-specialized functions.


Asunto(s)
Genómica , Proteínas de Insectos/metabolismo , Isópteros/fisiología , Evolución Social , Transcriptoma , Animales , Evolución Biológica , Celulasas/metabolismo , Femenino , Duplicación de Gen , Expresión Génica , Perfilación de la Expresión Génica , Proteínas de Insectos/genética , Isópteros/genética
10.
Sci Rep ; 11(1): 15992, 2021 08 06.
Artículo en Inglés | MEDLINE | ID: mdl-34362973

RESUMEN

The sex determination gene doublesex (dsx) encodes a transcription factor with two domains, oligomerization domain 1 (OD1) and OD2, and is present throughout insects. Sex-specific Dsx splicing isoforms regulate the transcription of target genes and trigger sex differentiation in all Holometabola examined to date. However, in some hemimetabolous insects, dsx is not spliced sexually and its sequence is less conserved. Here, to elucidate evolutionary changes in dsx in domain organisation and regulation in termites, we searched genome and/or transcriptome databases for the dsx OD1 and OD2 in seven termite species and their sister group (Cryptocercus woodroaches). Molecular phylogenetic and synteny analyses identified OD1 sequences of termites and C. punctulatus that clustered with dsx of Holometabola and regarded them as dsx orthologues. The Cryptocercus dsx orthologue containing OD2 was spliced sexually, as previously shown in other insects. However, OD2 was not found in all termite dsx orthologues. These orthologues were encoded by a single exon in three termites for which genome information is available; they were not alternatively spliced but transcribed in a male-specific manner in two examined species. Evolution of dsx regulation from sex-specific splicing to male-specific transcription may have occurred at an early stage of social evolution in termites.


Asunto(s)
Evolución Biológica , Regulación de la Expresión Génica , Proteínas de Insectos/genética , Isópteros/genética , Empalme del ARN , Factores de Transcripción/genética , Animales , Sitios de Unión , Femenino , Isópteros/metabolismo , Masculino , Isoformas de Proteínas , RNA-Seq , Factores Sexuales , Factores de Transcripción/metabolismo
11.
J Clin Hypertens (Greenwich) ; 23(2): 334-344, 2021 02.
Artículo en Inglés | MEDLINE | ID: mdl-33400348

RESUMEN

Elevated serum uric acid is a cardiovascular risk factor in patients with hypertension, even when blood pressure (BP) is well controlled. Xanthine oxidoreductase inhibitors (XORi) reduce serum uric acid levels and have several other potential effects. This multicenter, randomized, open-label study compared the effects of two XORi, topiroxostat and febuxostat, on arterial stiffness, uric acid levels, and BP in hypertensive patients with hyperuricemia. Patients received topiroxostat 40-160 mg/day or febuxostat 10-60 mg/day, titrated to maintain serum uric acid <6 mg/dl, for 24 weeks. The primary endpoint was change in the cardio-ankle vascular index (CAVI) from baseline to 24 weeks. There were no significant changes in CAVI from baseline to 24 weeks (from 9.13 to 9.16 [feboxustat] and 8.98 to 9.01 [topiroxostat]). Compared with baseline, there were significant reductions in serum uric acid (-2.9 and -2.5 mg/dl; both p < 0.001) and morning home systolic BP (-3.6 and -5.1 mm Hg; both p < 0.01) after 24 weeks' treatment with febuxostat and topiroxostat. BP decreased to the greatest extent in the subgroup of patients with uncontrolled blood pressure at baseline. Topiroxostat, but not febuxostat, significantly decreased plasma xanthine oxidoreductase activity versus baseline. The urinary albumin-creatinine ratio (UACR) decreased significantly from baseline to 24 weeks with topiroxostat (-20.8%; p = 0.021), but not febuxostat (-8.8%; p = 0.362). In conclusion, neither topiroxostat nor febuxostat had any significant effects on arterial stiffness over 24 weeks' treatment.


Asunto(s)
Hipertensión , Hiperuricemia , Febuxostat/uso terapéutico , Supresores de la Gota/uso terapéutico , Humanos , Hipertensión/tratamiento farmacológico , Hiperuricemia/complicaciones , Hiperuricemia/tratamiento farmacológico , Nitrilos , Piridinas , Resultado del Tratamiento , Ácido Úrico
12.
J Evol Biol ; 33(9): 1192-1202, 2020 09.
Artículo en Inglés | MEDLINE | ID: mdl-33448532

RESUMEN

The ability to express different phenotypes can help define species distributions by allowing access to, and exploitation of, new environments. Social insects employ two markedly different reproductive strategies with contrasting cost/benefit characteristics: independent colony foundation (ICF), which is associated with high dispersal range and high risk, and dependent colony foundation (DCF), characterized by low risk but low dispersal. The ant Myrmecina nipponica employs both of these strategies, with the frequency of each apparently varying between populations. We combine molecular data with data on reproductive strategy from different populations of this species throughout Japan to explore how this polymorphism is linked to environmental factors and whether this relationship can help explain the current and historical biogeography of this species. Reproductive strategy exhibited a strong geographic pattern, with ICF predominant in southern populations and DCF more common in northern and southern highland populations. Molecular analyses clearly divided populations into broad geographic regions, with the southern lowland populations basal to (southern highland (+ northern)) populations. Intra-population polymorphism in colony-founding strategy was widespread, and polymorphism was reconstructed as the likely ancestral state. The frequency of different strategies was linked with climate, with DCF more common in colder areas. A recent inferred origin to the northern lineage suggests that colonization of northern Japan was a rapid event coincident with warming at the end of the Last Glacial Maxima, likely facilitated by the cold-adaptive advantages of DCF. We discuss how such polymorphisms could help explain the biogeography of this and other social insects.


Asunto(s)
Hormigas/genética , Conducta Animal , Animales , Femenino , Japón , Filogeografía , Polimorfismo Genético , Reproducción
13.
Proc Biol Sci ; 285(1883)2018 07 25.
Artículo en Inglés | MEDLINE | ID: mdl-30051867

RESUMEN

Social communication among castes is a crucial component of insect societies. However, the genes involved in soldier determination through the regulation of inter-individual interactions are largely unknown. In an incipient colony of the damp-wood termite Zootermopsis nevadensis, the first larva to develop into a third instar always differentiates into a soldier via frequent trophallactic feeding from the reproductives. Here, by performing RNA-seq analysis of third instar larvae, a homologue of Neural Lazarillo (named ZnNLaz1) was found to be the most differentially expressed gene in these soldier-destined larvae, compared with worker-destined larvae. This gene encodes a lipocalin protein related to the transport of small hydrophobic molecules. RNAi-induced knockdown of ZnNLaz1 significantly inhibited trophallactic interactions with the queen and decreased the soldier differentiation rates. This protein is localized in the gut, particularly in the internal wall, of soldier-destined larvae, suggesting that it is involved in the integration of social signals from the queen through frequent trophallactic behaviours. Based on molecular phylogenetic analysis, we suggest that a novel function of termite NLaz1 has contributed to social evolution from the cockroach ancestors of termites. These results indicated that a high larval NLaz1 expression is crucial for soldier determination through social communication in termites.


Asunto(s)
Proteínas de Insectos/genética , Isópteros/fisiología , Lipocalinas/genética , Animales , Femenino , Expresión Génica , Proteínas de Insectos/metabolismo , Isópteros/genética , Isópteros/crecimiento & desarrollo , Larva/genética , Larva/crecimiento & desarrollo , Larva/fisiología , Lipocalinas/metabolismo , Masculino , Dinámica Poblacional , Conducta Social
14.
Nature ; 550(7674): 80-83, 2017 10 04.
Artículo en Inglés | MEDLINE | ID: mdl-28980637

RESUMEN

Type Ia supernovae arise from the thermonuclear explosion of white-dwarf stars that have cores of carbon and oxygen. The uniformity of their light curves makes these supernovae powerful cosmological distance indicators, but there have long been debates about exactly how their explosion is triggered and what kind of companion stars are involved. For example, the recent detection of the early ultraviolet pulse of a peculiar, subluminous type Ia supernova has been claimed as evidence for an interaction between a red-giant or a main-sequence companion and ejecta from a white-dwarf explosion. Here we report observations of a prominent but red optical flash that appears about half a day after the explosion of a type Ia supernova. This supernova shows hybrid features of different supernova subclasses, namely a light curve that is typical of normal-brightness supernovae, but with strong titanium absorption, which is commonly seen in the spectra of subluminous ones. We argue that this early flash does not occur through previously suggested mechanisms such as the companion-ejecta interaction. Instead, our simulations show that it could occur through detonation of a thin helium shell either on a near-Chandrasekhar-mass white dwarf, or on a sub-Chandrasekhar-mass white dwarf merging with a less-massive white dwarf. Our finding provides evidence that one branch of previously proposed explosion models-the helium-ignition branch-does exist in nature, and that such a model may account for the explosions of white dwarfs in a mass range wider than previously supposed.

15.
PLoS One ; 12(4): e0176055, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28448596

RESUMEN

BACKGROUNDS: Hypouricemia was reported as a risk factor for exercise-induced acute renal injury (EIAKI) and urinary stones. However, the prevalence of kidney diseases among hypouricemic subjects has not been evaluated. This study was conducted to clarify the prevalence of hypouricemia and the association of hypouricemia with kidney diseases by using a large-scale Japanese population data. METHODS: This study is a retrospective cross-sectional study at the Center for Preventive Medicine, St. Luke's International Hospital, Tokyo, Japan, and Sanin Rousai Hospital, Yonago, Japan. We analyzed the medical records of 90,143 Japanese subjects at the center in St. Luke's International Hospital, Tokyo, and 4,837 subjects in Sanin Rousai Hospital, Yonago, who underwent annual regular health check-up between January 2004 and June 2010. We defined hypouricemia as serum uric acid level of ≤2.0 mg/dL. We checked the medical history of all the study subjects and compared the rates of complications including urinary stones and kidney diseases among those with or without hypouricemia. RESULTS: The prevalence of hypouricemia was 0.19% in St. Luke's International Hospital, Tokyo, and 0.58% in Sanin Rousai Hospital, Yonago. The prevalence of hypouricemia in women was larger than that in men both in Tokyo (0.31% vs 0.068%, p<0.001) and in Yonago (1.237% vs 0.318%, p<0.001). Among 172 hypouricemic subjects (30 men), the rates of previous urinary stones and kidney diseases (including nephritis/nephrosis) were 1.2% (3.3% men, 0.7% women) and 2.3% (10% men, 0.7% women), respectively. Hypouricemic men had a 9-fold higher rate of previously having kidney diseases compared to non-hypouricemic men (p<0.001). However, the rates of other diseases including urinary stones were not significantly different between the two groups. CONCLUSIONS: Hypouricemia was associated with a history of kidney disease especially in men.


Asunto(s)
Enfermedades Renales/complicaciones , Defectos Congénitos del Transporte Tubular Renal/epidemiología , Cálculos Urinarios/epidemiología , Adulto , Estudios Transversales , Femenino , Hospitales , Humanos , Japón/epidemiología , Masculino , Persona de Mediana Edad , Prevalencia , Defectos Congénitos del Transporte Tubular Renal/etiología , Estudios Retrospectivos , Factores Sexuales , Ácido Úrico/sangre , Cálculos Urinarios/etiología
16.
Biochem Biophys Res Commun ; 485(2): 261-266, 2017 04 01.
Artículo en Inglés | MEDLINE | ID: mdl-28235482

RESUMEN

Activation-induced cytidine deaminase (AID) is essential for diversification of the Ig variable region (IgV). AID is excluded from the nucleus, where it normally functions. However, the molecular mechanisms responsible for regulating AID localization remain to be elucidated. The SR-protein splicing factor SRSF1 is a nucleocytoplasmic shuttling protein, a splicing isoform of which called SRSF1-3, has previously been shown to contribute to IgV diversification in chicken DT40 cells. In this study, we examined whether SRSF1-3 functions in IgV diversification by promoting nuclear localization of AID. AID expressed alone was localized predominantly in the cytoplasm. In contrast, co-expression of AID with SRSF1-3 led to the nuclear accumulation of both AID and SRSF1-3 and the formation of a protein complex that contained them both, although SRSF1-3 was dispensable for nuclear import of AID. Expression of either SRSF1-3 or a C-terminally-truncated AID mutant increased IgV diversification in DT40 cells. However, overexpression of exogenous SRSF1-3 was unable to further enhance IgV diversification in DT40 cells expressing the truncated AID mutant, although SRSF1-3 was able to form a protein complex with the AID mutant. These results suggest that SRSF1-3 promotes nuclear localization of AID probably by forming a nuclear protein complex, which might stabilize nuclear AID and induce IgV diversification in an AID C-terminus-dependent manner.


Asunto(s)
Proteínas Aviares/genética , Proteínas Aviares/metabolismo , Pollos/genética , Citidina Desaminasa/metabolismo , Región Variable de Inmunoglobulina/genética , Factores de Empalme Serina-Arginina/metabolismo , Hipermutación Somática de Inmunoglobulina , Transporte Activo de Núcleo Celular , Animales , Línea Celular , Núcleo Celular/genética , Núcleo Celular/metabolismo , Pollos/metabolismo , Conversión Génica
17.
J Exp Biol ; 218(Pt 7): 1091-8, 2015 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-25687437

RESUMEN

In social Hymenoptera with no morphological caste, a dominant female becomes an egg layer, whereas subordinates become sterile helpers. The physiological mechanism that links dominance rank and fecundity is an essential part of the emergence of sterile females, which reflects the primitive phase of eusociality. Recent studies suggest that brain biogenic amines are correlated with the ranks in dominance hierarchy. However, the actual causality between aminergic systems and phenotype (i.e. fecundity and aggressiveness) is largely unknown due to the pleiotropic functions of amines (e.g. age-dependent polyethism) and the scarcity of manipulation experiments. To clarify the causality among dominance ranks, amine levels and phenotypes, we examined the dynamics of the aminergic system during the ontogeny of dominance hierarchy in the queenless ant Diacamma sp., which undergoes rapid physiological differentiation based on dominance interactions. Brain dopamine levels differed between dominants and subordinates at day 7 after eclosion, although they did not differ at day 1, reflecting fecundity but not aggressiveness. Topical applications of dopamine to the subordinate workers induced oocyte growth but did not induce aggressiveness, suggesting the gonadotropic effect of dopamine. Additionally, dopamine receptor transcripts (dopr1 and dopr2) were elevated in the gaster fat body of dominant females, suggesting that the fat body is a potential target of neurohormonal dopamine. Based on this evidence, we suggest that brain dopamine levels are elevated in dominants as a result of hierarchy formation, and differences in dopamine levels cause the reproductive differentiation, probably via stimulation of the fat body.


Asunto(s)
Hormigas/fisiología , Dopamina/metabolismo , Factores de Edad , Animales , Encéfalo/metabolismo , Dopamina/farmacología , Cuerpo Adiposo/metabolismo , Femenino , Fertilidad , Regulación del Desarrollo de la Expresión Génica , Octopamina/farmacología , Oogénesis , Receptores Dopaminérgicos/genética , Receptores Dopaminérgicos/metabolismo , Transducción de Señal , Predominio Social
18.
BMC Evol Biol ; 14: 177, 2014 Aug 14.
Artículo en Inglés | MEDLINE | ID: mdl-25123355

RESUMEN

BACKGROUND: In insect societies, intracolonial genetic variation is predicted to affect both colony efficiency and reproductive skew. However, because the effects of genetic variation on these two colony characteristics have been tested independently, it remains unclear whether they are affected by genetic variation independently or in a related manner. Here we test the effect of genetic variation on colony efficiency and reproductive skew in a rhinotermitid termite, Reticulitermes speratus, a species in which female-female pairs can facultatively found colonies. We established colonies using two types of female-female pairs: colonies founded by sisters (i.e., sister-pair colonies) and those founded by females from different colonies (i.e., unrelated-pair colonies). Colony growth and reproductive skew were then compared between the two types of incipient colonies. RESULTS: At 15 months after colony foundation, unrelated-pair colonies were larger than sister-pair colonies, although the caste ratio between workers and nymphs, which were alternatively differentiated from young larvae, did not differ significantly. Microsatellite DNA analyses of both founders and their parthenogenetically produced offspring indicated that, in both sister-pair and unrelated-pair colonies, there was no significant skew in the production of eggs, larvae, workers and soldiers. Nymph production, however, was significantly more skewed in the sister-pair colonies than in unrelated-pair colonies. Because nymphs can develop into winged adults (alates) or nymphoid reproductives, they have a higher chance of direct reproduction than workers in this species. CONCLUSIONS: Our results support the idea that higher genetic variation among colony members could provide an increase in colony productivity, as shown in hymenopteran social insects. Moreover, this study suggests that low genetic variation (high relatedness) between founding females increases reproductive skew via one female preferentially channeling her relatives along the reproductive track. This study thus demonstrated that, in social insects, intracolonial genetic variation can simultaneously affect both colony efficiency and reproductive skew.


Asunto(s)
Variación Genética , Isópteros/genética , Animales , Femenino , Isópteros/clasificación , Isópteros/crecimiento & desarrollo , Isópteros/fisiología , Masculino , Repeticiones de Microsatélite , Partenogénesis , Reproducción
19.
PLoS One ; 9(3): e92875, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24667821

RESUMEN

Most hymenopteran species exhibit conspicuous sexual dimorphism due to ecological differences between the sexes. As hymenopteran genomes, under the haplodiploid genetic system, exhibit quantitative differences between sexes while remaining qualitatively identical, sexual phenotypes are assumed to be expressed through sex-specific gene usage. In the present study, the molecular basis for expression of sexual dimorphism in a queenless ant, Diacamma sp., which exhibits a distinct color dimorphism, was examined. Worker females of the species appear bluish-black, while winged males exhibit a yellowish-brown body color. Initially, observations of the pigmentation processes during pupal development revealed that black pigmentation was present in female pupae but not in males, suggesting that sex-specific melanin synthesis was responsible for the observed color dimorphism. Therefore, five orthologs of the genes involved in the insect melanin synthesis (yellow, ebony, tan, pale and dopa decarboxylase) were subcloned and their spatiotemporal expression patterns were examined using real-time quantitative RT-PCR. Of the genes examined, yellow, which plays a role in black melanin synthesis in insects, was expressed at higher levels in females than in males throughout the entire body during the pupal stage. RNA interference of yellow was then carried out in order to determine the gene function, and produced females with a more yellowish, brighter body color similar to that of males. It was concluded that transcriptional regulation of yellow was responsible for the sexual color dimorphism observed in this species.


Asunto(s)
Hormigas/metabolismo , Proteínas de Insectos/metabolismo , Pigmentación/fisiología , Caracteres Sexuales , Factores de Transcripción/metabolismo , Animales , Hormigas/genética , Femenino , Proteínas de Insectos/genética , Masculino , Melaninas/biosíntesis , Melaninas/genética , Factores de Transcripción/genética
20.
Clin Exp Hypertens ; 36(7): 447-53, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24433018

RESUMEN

PURPOSE: To examine effects of a long-acting calcium channel blocker (CCB) azelnidipine on uric acid metabolism in hypertensive patients. METHODS: Azelnidipine was administered to 72 patients at a daily dose of 8 mg or 16 mg. In 22 cases out of the 72 patients, a different CCB was switched to azelnidipine. Blood pressure was measured and biochemical parameters of blood and urine were evaluated before and 2-3 months after the administration. RESULTS: Azelnidipine significantly decreased both systolic and diastolic blood pressure and the heart rate. It decreased both serum urate levels and the urinary uric acid to creatinine ratio (Uur/Ucr), but did not affect the uric acid clearance to creatinine clearance ratio (Cur/Ccr). Azelnidipine decreased both Uur/Ucr and Cur/Ccr in patients with Uur/Ucr ≥ 0.5 or ≥ 0.34, although it did not change these clearance parameters in patients with Uur/Ucr <0.5 or <0.34. Azelnidipine decreased the serum urate levels and Uur/Ucr in hyperuricemic patients with uric acid levels ≥ 7.0 mg/dL in males and ≥ 6.0 mg/dL in females. It did not change these parameters in normouricemic patients with serum urate levels <7.0 mg/dL in males and <6.0 mg/dL in females. Azelnidipine decreased Uur/Ucr and Cur/Ccr in hyperuricemic patients with normal or over excretion of uric acid, although it did not change these clearance parameters in hyperuricemic patients with uric acid hypoexcretion. CONCLUSIONS: Azelnidipine decreased the serum urate acid levels and Uur/Ucr, and this response was most prominent in hyperuricemic patients or patients with normal and over excretion of uric acid.


Asunto(s)
Ácido Azetidinocarboxílico/análogos & derivados , Bloqueadores de los Canales de Calcio/uso terapéutico , Dihidropiridinas/uso terapéutico , Hipertensión/tratamiento farmacológico , Hipertensión/metabolismo , Hiperuricemia/tratamiento farmacológico , Ácido Úrico/metabolismo , Anciano , Anciano de 80 o más Años , Ácido Azetidinocarboxílico/uso terapéutico , Presión Sanguínea/efectos de los fármacos , Creatinina/metabolismo , Hipertensión Esencial , Femenino , Humanos , Hipertensión/complicaciones , Hiperuricemia/complicaciones , Hiperuricemia/metabolismo , Masculino , Ácido Úrico/sangre , Ácido Úrico/orina
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