Hidden social complexity behind vocal and acoustic communication in non-avian reptiles.

Social interactions are inevitable in the lives of most animals, since most essential behaviours require interaction with conspecifics, such as mating and competing for resources. Non-avian reptiles are typically viewed as solitary animals that predominantly use their vision and olfaction to communicate with conspecifics. Nevertheless, in recent years, evidence is mounting that some reptiles can produce sounds and have the potential for acoustic communication. Reptiles that can produce sound have an additional communicative channel (in addition to visual/olfactory channels), which could suggest they have a higher communicative complexity, the evolution of which is assumed to be driven by the need of social interactions. Thus, acoustic reptiles may provide an opportunity to unveil the true social complexity of reptiles that are usually thought of as solitary. This review aims to reveal the hidden social interactions behind the use of sounds in non-avian reptiles. Our review suggests that the potential of vocal and acoustic communication and the complexity of social interactions may be underestimated in non-avian reptiles, and that acoustic reptiles may provide a great opportunity to uncover the coevolution between sociality and communication in non-avian reptiles. This article is part of the theme issue 'The power of sound: unravelling how acoustic communication shapes group dynamics'.

Trained quantity discrimination in invasive red-eared slider and a comparison with the native stripe-necked turtle.

Little is known about the behavioral and cognitive traits that best predict invasion success. Evidence is mounting that cognitive performance correlates with survival and fecundity, two pivotal factors for the successful establishment of invasive populations. We assessed the quantity discrimination ability of the globally invasive red-eared slider (Trachemys scripta elegans). We further compared it to that of the native stripe-necked turtle (Mauremys sinensis), which has been previously evaluated for its superior quantity discrimination ability. Specifically, our experimental designs aimed to quantify the learning ability as numerosity pairs increased in difficulty (termed fixed numerosity tests), and the immediate response when turtles were presented with varied challenges concurrently in the same tests (termed mixed numerosity tests). Our findings reaffirm the remarkable ability of freshwater turtles to discern numerical differences as close as 9 vs 10 (ratio = 0.9), which was comparable to the stripe-necked turtle's performance. However, the red-eared slider exhibited a moderate decrease in performance in high ratio tests, indicating a potentially enhanced cognitive capacity to adapt to novel challenges. Our experimental design is repeatable and is adaptable to a range of freshwater turtles. These findings emphasize the potential importance of cognitive research to the underlying mechanisms of successful species invasions.

Graph theoretical analysis and independent component analysis of diabetic optic neuropathy: A resting-state functional magnetic resonance imaging study.

AIMS: This study aimed to investigate the resting-state functional connectivity and topologic characteristics of brain networks in patients with diabetic optic neuropathy (DON). METHODS: Resting-state functional magnetic resonance imaging scans were performed on 23 patients and 41 healthy control (HC) subjects. We used independent component analysis and graph theoretical analysis to determine the topologic characteristics of the brain and as well as functional network connectivity (FNC) and topologic properties of brain networks. RESULTS: Compared with HCs, patients with DON showed altered global characteristics. At the nodal level, the DON group had fewer nodal degrees in the thalamus and insula, and a greater number in the right rolandic operculum, right postcentral gyrus, and right superior temporal gyrus. In the internetwork comparison, DON patients showed significantly increased FNC between the left frontoparietal network (FPN-L) and ventral attention network (VAN). Additionally, in the intranetwork comparison, connectivity between the left medial superior frontal gyrus (MSFG) of the default network (DMN) and left putamen of auditory network was decreased in the DON group. CONCLUSION: DON patients altered node properties and connectivity in the DMN, auditory network, FPN-L, and VAN. These results provide evidence of the involvement of specific brain networks in the pathophysiology of DON.

A new species of the Cyrtodactylusquadrivirgatus complex (Chordata, Reptilia, Squamata, Gekkonidae) from Sumatra Barat, Indonesia.

Among the six species of Cyrtodactylus occurring in Sumatra, two species were described based on non-Sumatran type series, C.consobrinus and C.quadrivirgatus. The latter species was described originally from Thailand thus the wider distribution in Sumatra should be clarified taxonomically. Cyrtodactylusquadrivirgatus from Sumatra Barat was examined using both morphology and the Natrium Dehydrogenase Subunit 2 (ND2) gene to clarify its taxonomic status and phylogenetic placement. It was found that these specimens form a sister clade to all other species of the sworderi group from Peninsular Malaysia and the genetic distance ranges from 20-24.3%. This subset is herein described as a new species. The new species is readily distinguished from C.quadrivirgatus and other Sumatran species by a combination of characters: small size SVL 37.5-53.78 mm; longitudinal rows of dorsal tubercles 16-19; paravertebral tubercles 31-41; ventral scales 32-43; 24-49 enlarged precloacal and femoral scales; precloacal pores rarely present; no precloacal depression; two postcloacal tubercles on each side; 14-19 subdigital lamellae on forth toe; 9-15 supralabial scales; 9-12 infralabial scales; three or four internasal scales; and 3-6 gular scales that border the first pair of postmental scales. This work underscores the importance of clarifying widely distributed species for taxonomic validation.

MACC1 and Gasdermin-E (GSDME) regulate the resistance of colorectal cancer cells to irinotecan.

Metastasis-associated in colon cancer 1 (MACC1) is an oncogene associated with the progression and metastasis of many solid cancer entities. High expression of MACC1 is found in colorectal cancer (CRC) tissues. So far, the role of MACC1 in CRC cell pyroptosis and resistance to irinotecan is unclear. The cleavage of Gasdermin-E (GSDME) is the main executors of activated pyroptosis. We found that GSDME enhanced CRC cell pyroptosis and reduced their resistance to irinotecan, while MACC1 inhibited the cleavage of GSDME and CRC cell pyroptosis, promoted CRC cell proliferation, and enhanced the resistance of CRC cells to irinotecan. Therefore, CRC cells with high MACC1 expression and low GSDME expression had higher resistance to irinotecan, while CRC cells with low MACC1 expression and high GSDME expression had lower resistance to irinotecan. Consistently, by analyzing CRC patients who received FOLFIRI (Fluorouracil + Irinotecan + Leucovorin) in combination with chemotherapy in the GEO database, we found that CRC patients with low MACC1 expression and high GSDME expression had higher survival rate. Our study suggests that the expression of MACC1 and GSDME can be used as detection markers to divide CRC patients into irinotecan resistant and sensitive groups, helping to determine the treatment strategy of patients.

Common but ignored: a new species of Cyrtodactylus (Chordata, Reptilia, Squamata, Gekkonidae) from lowland Sumatra Barat, Indonesia.

The lowland region of Sumatra Barat has received little attention in previous biodiversity studies. Past studies have mainly focused on highland habitat and conservation areas. However, many populations of Cyrtodactylus in the lowland habitats of Sumatra Barat were not correctly identified. A phylogenetic tree based on the NADH dehydrogenase subunit 2 (ND2) gene showed that the lowland Sumatran population is the sister group of the Malaysian lowland species, C.semenanjungensis, together nesting within the agamensis group. The genetic divergence within the Sumatra Barat population is 0-4.2% and 18.3-20% to C.semenanjungensis. Further examination of morphological characters revealed that they differed from the sister clade and other Sumatran Cyrtodactylus members by a unique combination of characters such as absence of tubercle on brachium, presence of tubercle on ventrolateral fold, 32-41 paravertebral tubercles, 38-46 ventral scales, enlarged femoral scales, presence of precloacofemoral pores and 22-23 subdigital lamellae under fourth toe. Based on the morphological and molecular evidence, the lowland Sumatran population is herein described as a new species, increasing the number of species in Sumatra to seven. More comprehensive and intensive sampling efforts would most likely yield further discoveries in the group of Sumatran Cyrtodactylus in the near future.

Highly rapid and diverse sex chromosome evolution in the Odorrana frog species complex.

Sex chromosomes in poikilothermal vertebrates are characterized by rapid and diverse evolution at the species or population level. Our previous study revealed that the Taiwanese frog Odorrana swinhoana (2n = 26) has a unique system of multiple sex chromosomes created by three sequential translocations among chromosomes 1, 3, and 7. To reveal the evolutionary history of sex chromosomes in the Odorrana species complex, we first identified the original, homomorphic sex chromosomes, prior to the occurrence of translocations, in the ancestral-type population of O. swinhoana. Then, we extended the investigation to a closely related Japanese species, Odorrana utsunomiyaorum, which is distributed on two small islands. We used a high-throughput nuclear genomic approach to analyze single-nucleotide polymorphisms and identify the sex-linked markers. Those isolated from the O. swinhoana ancestral-type population were found to be aligned to chromosome 1 and showed male heterogamety. In contrast, almost all the sex-linked markers isolated from O. utsunomiyaorum were heterozygous in females and homozygous in males and were aligned to chromosome 9. Morphologically, we confirmed chromosome 9 to be heteromorphic in females, showing a ZZ-ZW sex determination system, in which the W chromosomes were heterochromatinized in a stripe pattern along the chromosome axis. These results indicated that after divergence of the two species, the ancestral homomorphic sex chromosome 1 underwent highly rapid and diverse evolution, i.e., sequential translocations with two autosomes in O. swinhoana, and turnover to chromosome 9 in O. utsunomiyaorum, with a transition from XY to ZW heterogamety and change to heteromorphy.

The Asian turtle tick Amblyomma geoemydae Cantor, 1847 (Acari: Ixodidae) in the Philippines: first confirmed local host and locality with a complete host index.

Amblyomma geoemydae is an oriental tick species primarily associated with turtles and tortoises but also sometimes reported from other vertebrates, including humans. Although A. geoemydae was first reported from the Philippines more than 70 years ago, it has not been reported since, and no local distributional or host data have been published. Herein, we present the first definitive locality report and host record for A. geoemydae in the Philippines. A complete checklist of the known host species from which A. geoemydae has been collected is also presented.

Do I stay or do I go? Shifts in perch use by lizards during morning twilight suggest anticipatory behaviour.

Anticipatory behaviour is the expectation of a near-future event based on information processed in the past and influences an animal's tactical decisions, particularly when there are significant fitness consequences. The grass lizard (Takydromus viridipunctatus) perches on blades of grass at night which likely reduces the probability of predation by terrestrial predators such as snakes, rodents and shrews. During twilight (starting 30 min before sunrise), they move from above the grass to within grass clumps and this is thought to afford the lizard protection while reducing detection by avian predators. Here, we examined how lizards shift their behaviour as a function of visual detectability to their primary predator, the cattle egret (Bubulcus ibis). We show that the lizards shift from their perch site during twilight at the earliest time at which egrets depart communal roosts. At the same time, visual modelling shows a dramatic increase in the detectability of the lizards to the visual system of egrets. Therefore, anticipatory behaviour in response to environmental cues acts to reduce predation risk as lizards become more conspicuous and predators become more active. Grass lizard anticipatory behaviour appears to be finely tuned by natural selection to adjust to temporal changes in predation risk.

Superior continuous quantity discrimination in a freshwater turtle.

BACKGROUND: Quantity discrimination, the ability to discriminate a magnitude of difference or discrete numerical information, plays a key role in animal behavior. While quantitative ability has been well documented in fishes, birds, mammals, and even in previously unstudied invertebrates and amphibians, it is still poorly understood in reptiles and has never been tested in an aquatic turtle despite the fact that evidence is accumulating that reptiles possess cognitive skills and learning ability. To help address this deficiency in reptiles, we investigated the quantitative ability of an Asian freshwater turtle, Mauremys sinensis, using red cubes on a white background in a trained quantity discrimination task. While spontaneous quantity discrimination methods are thought to be more ecologically relevant, training animals on a quantity discrimination task allows more comparability across taxa. RESULTS: We assessed the turtles' quantitative performance in a series of tests with increasing quantity ratios and numerosities. Surprisingly, the turtles were able to discriminate quantities of up to 9 versus 10 (ratio = 0.9), which shows a good quantitative ability that is comparable to some endotherms. Our results showed that the turtles' quantitative performance followed Weber's law, in which success rate decreased with increasing quantity ratio across a wide range of numerosities. Furthermore, the gradual improvement of their success rate across different experiments and phases suggested that the turtles possess learning ability. CONCLUSIONS: Reptile quantitative ability has long been ignored and therefore is likely under-estimated. More comparative research on numerical cognition across a diversity of species will greatly contribute to a clearer understanding of quantitative ability in animals and whether it has evolved convergently in diverse taxa.

Taxonomic clarification and neotype designation of two Taiwanese salamanders (Amphibia, Urodela, Hynobiidae).

Taxonomic identification of two Taiwanese salamanders, Hynobius sonani (Maki, 1922), and H. formosanus Maki, 1922, was clarified. Based on the descriptions and measurement data in the original description, we confirmed that H. sonani has been treated as H. formosanus and vice versa, which might have been caused by confusion of sampling localities of the two species. Because we could not find the holotypes of the two species and concluded these were lost, we herein assign neotypes for these species for precluding future taxonomic confusion.

Eggs survive through avian guts-A possible mechanism for transoceanic dispersal of flightless weevils.

How flightless animals disperse to remote oceanic islands is a key unresolved question in biogeography. The flightless Pachyrhynchus weevils represent repetitive colonization history in West Pacific islands, which attracted our interests about how some weevils have successfully dispersed in the reverse direction against the sea current. Here, we propose endozoochory as a possible mechanism that the eggs of the weevils might be carried by embedded in the fruits as the food of frugivorous birds. In this study, Pachyrhynchus eggs were embedded in small pieces of persimmon fruits (Diospyros kaki) and fed to captive frugivorous birds. After digestion, 83%-100% eggs were retrieved from the feces of a bulbul (Hypsipetes leucocephalus) and two thrushes (Turdus chrysolaus). The retrieved eggs had hatching rates higher than 84%, which were not different from the control. In contrast, no egg was retrieved from the feces of the frugivorous pigeon (Treron sieboldii), which took a longer retention time in the guts. Our study identified that the eggs of Pachyrhynchus weevils are possible to be transported by internal digesting in some bird species.

Association between neutrophils and renal impairment of rheumatoid arthritis: A retrospective cross-sectional study.

OBJECTIVE: Previous studies have shown that increased neutrophils, as a manifestation of oxidative stress, may be involved in the progression of kidney disease. To our knowledge, little is known about the relationship between neutrophils and renal impairment in rheumatoid arthritis (RA). Therefore, we aim to investigate whether neutrophil is associated with renal impairment in RA patients. METHODS: We retrospectively investigated the renal function of 602 RA patients in the First Affiliated Hospital of Guangzhou University of Traditional Chinese Medicine by estimated glomerular filtration rate (eGFR) from September 2018 and September 2019. The exposure variable was neutrophils, and the main outcome was eGFR. General data (gender, age, duration, hypertension, diabetes, hobbies, and medication history), whole blood markers, lipid indexes, and inflammatory indexes were collected as much as possible. We used multivariable logistic regression analysis to evaluate the association between neutrophils and renal impairment in RA participants. RESULTS: A total of 89 cases (14.8%) had renal impairment with eGFR < 60 ml/min/1.73 m2 , and 75 cases (84.3%) were female. Subgroup analysis showed that female (odds ratio [OR] = 0.523, 95% confidence interval [CI]: 0.318-0.867, p = .011), neutrophils greater thsn 7.5 × 109 /L (OR = 2.314, 95% CI: 1.310-4.087, p = .004), NLR > 3.53 (OR = 1.757, 95% CI: 1.104-2.799, p = .018), hemoglobin less than 120 g/L (OR = 2.413, 95% CI: 1.418-4.118, p = .001), and UA > 360 µmol/L (OR = 6.052, 95% CI: 3.708-9.878, p < .001) was related to renal damage in RA. Adjusted for several confounders, the multivariable analysis indicated that neutrophils greater than 7.5 × 109 /L (OR = 1.784, 95% CI: 1.164-3.288, p = .031) was independently associated with an increased risk of renal impairment in RA. CONCLUSION: Our study demonstrated that neutrophils greater than 7.5 × 109 /L was associated with a high risk of renal impairment in RA, suggesting that neutrophil may be a biomarker for renal impairment in RA.

Evolution of a Multiple Sex-Chromosome System by Three-Sequential Translocations among Potential Sex-Chromosomes in the Taiwanese Frog Odorrana swinhoana.

Translocation between sex-chromosomes and autosomes generates multiple sex-chromosome systems. It happens unexpectedly, and therefore, the evolutionary meaning is not clear. The current study shows a multiple sex chromosome system comprising three different chromosome pairs in a Taiwanese brown frog (Odorrana swinhoana). The male-specific three translocations created a system of six sex-chromosomes, ♂X1Y1X2Y2X3Y3-♀X1X1X2X2X3X3. It is unique in that the translocations occurred among three out of the six members of potential sex-determining chromosomes, which are known to be involved in sex-chromosome turnover in frogs, and the two out of three include orthologs of the sex-determining genes in mammals, birds and fishes. This rare case suggests sex-specific, nonrandom translocations and thus provides a new viewpoint for the evolutionary meaning of the multiple sex chromosome system.

Niche partitioning among three snail-eating snakes revealed by dentition asymmetry and prey specialisation.

The level of dentition asymmetry in snail-eating snakes may reflect their prey choice and feeding efficiency on asymmetric land snails. The three species of Pareas snakes (Squamata: Pareidae) in Taiwan, which form partially sympatric distribution on the island, provide a potential case to test the hypothesis of niche partitioning and character displacement with regard to dentition asymmetry and specialisation in feeding behaviour. In this study, behavioural experiments confirmed that P. formosensis feeds exclusively on slugs, whereas P. atayal and P. komaii consumed both. However, P. atayal more efficiently preys on land snails than P. komaii, exhibiting a shorter handling time and fewer mandibular retractions. Micro-CT and ancestral character reconstruction demonstrated the lowest asymmetry in P. formosensis (the slug specialist), the highest dentition asymmetry in P. atayal (the land snail specialist) and flexibility in P. komaii (the niche switcher): increased dentition asymmetry when sympatrically distributed with the slug eater (character displacement), and decreased asymmetry when living alone (ecological niche release). Ecological niche modelling showed that the distribution of P. formosensis is associated with the presence of slugs, while that of P. atayal could be explained by the land snails. Combining the results from morphology, phylogeny, behavioural experiments and ecological niche modelling, we showed that competition in the sympatric region might have facilitated character displacement among congeners, while the absence of competition in allopatric region has led to ecological niche release.

Comprehensive approaches reveal three cryptic species of genus Nidirana (Anura, Ranidae) from China.

Three cryptic species, which were previously reported as Nidirana adenopleura, are revealed on the basis of comprehensive approaches. Nidirana guangdongensis Lyu, Wan, and YY Wang, sp. nov. is distributed in Nanling Mountains and southern Luoxiao Mountains, Nidirana mangveni Lyu, Qi, and YY Wang, sp. nov. is known from northern Zhejiang, and Nidirana xiangica Lyu and YY Wang, sp. nov. occurs in Xiangjiang River Basin, while the true Nidirana adenopleura is designated from Taiwan Island, northern Fujian, southern Zhejiang, and central Jiangxi. These three new species can be distinguished from all congeners by significant divergences in the mitochondrial 16S and CO1 genes, differences in advertisement calls, and the combination of multiple characteristics. This work indicates that the current records of Nidirana adenopleura should be of a species complex composed of multiple species and have clarified the true identity of N. adenopleura.

Long-term monitoring reveals invariant clutch size and unequal reproductive costs between sexes in a subtropical lacertid lizard.

Based on 20,000 records representing c. 11,000 individuals from an 8-year capture-mark-recapture (CMR) study, we tested and confirmed a new case of invariant clutch size (ICS) in a sexually dichromatic lacertid lizard, Takydromus viridipunctatus. In the grassland habitat of the early succession stage, females showed strictly low and invariant clutch size, multiple clutches in a breeding season, high reproductive potential, and annual breeding cycles that correspond to the emergence of male courtship coloration. The hatchlings mature quickly, and join the adult cohort for breeding within a few months, whereas adults show low survival rates and a short lifespan, such that most die within one year. Mortality increased in both sexes during the breeding season, especially in females, indicating an unequal cost of reproduction in survival. These life history characters may be explained by two non-exclusive hypotheses of ICS-arboreal hypothesis and predation hypothesis-within the ecological context of their habitat. Our study highlights a confirmed case of ICS, which adapts well to this r-selected grassland habitat that experiences seasonal fluctuation and frequent disturbance.

Sympatric competitors have driven the evolution of temporal activity patterns in Cnemaspis geckos in Southeast Asia.

It is often assumed that animals' temporal activity patterns are highly conserved throughout evolution. While most geckos are nocturnal, the species in the Cnemaspis genus are mostly diurnal (only a few are nocturnal). This raises a question about the evolution of a diel niche in the Cnemaspis genus. Cnemaspis geckos are distributed across Southeast Asia and are often sympatric with Cyrtodactylus, another widespread gecko genus in the same area. Since both genera are mainly rocky habitat specialists, we hypothesize that Cyrtodactylus may influence the temporal activity pattern of Cnemaspis when they are sympatric through competition. By analyzing habitat data, diel activity, and the existence of sympatric Cyrtodactylus species across the phylogeny of the Cnemaspis genus, we found (1) strong phylogenetic signals in the habitat use trait but not in temporal activity, suggesting that the diel niche of this genus is more labile compared with habitat niche, and (2) a significant association with the temporal activity pattern of Cnemaspis and the sympatry between the two genera, with the former tending to be diurnal when they are sympatric. Originated from a diurnal common ancestor, the release from competition with Cyrtodactylus species might open an opportunity for some Cnemaspis species to shift to nocturnal niches.

Engagement of Robo1 by Slit2 induces formation of a trimeric complex consisting of Src-Robo1-E-cadherin for E-cadherin phosphorylation and epithelial-mesenchymal transition.

Loss of E-cadherin elicits epithelial-mesenchymal transition (EMT). While both the Src family of membrane-associated non-receptor tyrosine kinases (SFKs) and Slit2 binding to Roundabout 1 (Robo1) have been shown to induce E-cadherin repression and EMT, whether these two signaling pathways are mechanistically coupled remains unknown in epithelial cells. Here we found that Slit2 and Robo1 overexpression activated Src kinases for tyrosine phosphorylation, degradation of E-cadherin and induction of EMT. Specific blockade of Slit2 binding to Robo1 inactivated Src, prevented E-cadherin phosphorylation and EMT induction. Biochemically, the cytoplasmic CC3 motif of Robo1 (CC3) bound directly to the SH2 and 3 domains of c-Src and the cytoplasmic domains of E-cadherin. Slit2 induced Robo1 association with endogenous c-Src and E-cadherin, whereas ectopic expression of CC3 dissociated this protein complex in colorectal epithelial cells. These results indicate that Slit2 not only induces Robo1 binding to Src, but also recruits Src to E-cadherin for tyrosine phosphorylation of E-cadherin, leading to E-cadherin degradation and EMT induction in colorectal epithelial cells.

A check list and population trends of invasive amphibians and reptiles in Taiwan.

Invasive species have impacted biodiversity all around the world. Among various ecosystems, islands are most vulnerable to these impacts due to their high ratio of endemism, highly specialized adaptation, and isolated and unique fauna. As with other subtropical islands, Taiwan faces constant risk of biological invasions and is currently ranked as one of the countries most affected by invasive amphibians and reptiles. In this paper, a comprehensive checklist of all known exotic amphibians and reptiles is provided, including twelve species which have successfully colonized Taiwan and six species with a controversial status. We provide an update on the knowledge of all these species including their distribution, colonization history, threats to native animals, and population trends based on literature records, fauna surveys, and data collected during invasive species eradication and control programs. A list of species with high invasive potentials is also provided. This study reports, for the first time, a comprehensive survey of invasive herpetofauna in Taiwan, which should provide a valuable reference to other regions which might suffer from similar invasion risk.