Zona pellucida family genes in Chinese pond turtle: identification, expression profiles, and role in the spermatozoa acrosome reaction†.

The zona pellucida (ZP) is an extracellular matrix that surrounds all vertebrate eggs, and it is involved in fertilization and species-specific recognition. Numerous in-depth studies of the ZP proteins of mammals, birds, amphibians, and fishes have been conducted, but systematic investigation of the ZP family genes and their role during fertilization in reptiles has not been reported to date. In this study, we identified six turtle ZP (Tu-ZP) gene subfamilies (Tu-ZP1, Tu-ZP2, Tu-ZP3, Tu-ZP4, Tu-ZPD, and Tu-ZPAX) based on whole genome sequence data from Mauremys reevesii. We found that Tu-ZP4 had large segmental duplication and was distributed on three chromosomes, and we also detected gene duplication in the other Tu-ZP genes. To evaluate the role of Tu-ZP proteins in sperm-egg binding, we assessed the expression pattern of these Tu-ZP proteins and their ability to induce the spermatozoa acrosome reaction in M. reevesii. In conclusion, this is the first report of the existence of gene duplication of Tu-ZP genes and that Tu-ZP2, Tu-ZP3, and Tu-ZPD can induce acrosome exocytosis of spermatogenesis in the reptile.

Oviductal sperm storage in the Chinese pond turtle, Mauremys reevesii, depends on androgen-based promotion of the BCL 2 anti-apoptotic pathway.

CONTEXT: Sperm storage is a complex and highly coordinated process that is regulated by a variety of factors. The BCL 2 protein family plays a key role in regulating apoptosis, and determines sperm survival. AIMS: The objective of this study was to explore the correlation between sperm storage and the BCL 2 protein family in the oviduct of Mauremys reevesii . METHODS: Hematoxylin-eosin (HE) staining, immunohistochemistry (IHC) and real-time quantitative polymerase chain reaction (RT-qPCR) techniques were used to investigate three parts of the reproductive tract (isthmus, uterus and vagina) of mated and unmated female M. reevesii . KEY RESULTS: Hematoxylin-eosin staining revealed many sperm stored in the oviduct. IHC showed positive immunostaining for the BCL 2 and BAX proteins in epithelial ciliated and glandular cells. RT-qPCR indicated that the mRNA expressions of anti-apoptotic genes (BCL 2 , MCL 1 , BCL- W , BCL-XL ) and the androgen receptor (AR) were significantly higher in mated turtles than unmated turtles. However, the expression of pro-apoptotic genes (BAX , BAD , BID and CASPASE 3 ) showed the opposite relationship. CONCLUSIONS: These results suggest that sperm entering the oviduct can promote the synthesis of anti-apoptotic genes to protect themselves from various degradation factors. IMPLICATIONS: These findings will help researchers understand the mechanisms of sperm storage.

Pubertal exposure to acrylamide disrupts spermatogenesis by interfering with meiotic progression in male mice.

Teenagers are a major group likely to love junk foods, such as potato chips and bread items, which contain high levels of acrylamide (AA). The increasing evidence suggests that AA exposure may be associated with decreased reproductive capacity in humans and animals. However, the reproductive toxicity of AA in pubertal males has not been fully elucidated. In this study, we evaluated the effects of pubertal AA exposure on adult spermatogenesis in male mice. Mice were exposed to AA at 0, 5, 10, 20, and 40 mg/kg/day by gavage from postnatal day 28 (PND28) to PND56. Our results showed that pubertal AA exposure increased apoptosis of germ cells in seminiferous tubules, decreased sperm concentration, and caused defects in sperm of adult mice. To explore the possible mechanisms of AA on spermatogenesis, the meiotic process was analyzed. The ratio of leptotene and zygotene spermatocytes increased, while the pachytene and diplotene spermatocytes decreased in AA-treated mice. Further analysis revealed that AA exposure disrupted the pattern of H2AX phosphorylation expansion, synapsis, and the crossover formation during meiotic prophase I (MPI). Taken together, these results indicate that pubertal AA exposure affects the spermatogenesis may be by disrupting the MPI progression of male mice.

Chromosome-level genome assembly of the Chinese three-keeled pond turtle (Mauremys reevesii) provides insights into freshwater adaptation.

Mauremys reevesii is an endangered freshwater turtle that symbolizes longevity in Chinese culture. Despite its importance, genetic studies of this species remain limited, with no genomic sequence reported to date. Here, we report a high-quality, chromosome-level genomic sequence of M. reevesii obtained using a combination of Nanopore and Hi-C sequencing technologies. The 2.37 Gb M. reevesii genome was assembled from a total of ~226.80 Gb of Nanopore sequencing data. The M. reevesii genome contig N50 is 34.73 Mb, the highest value in published turtle genomes. In total, 18,238 genes were functionally annotated. The contigs were clustered and ordered onto 27 pseudochromosomes covering ~96.55% of the genome assembled with Hi-C data. To explore genome evolution, synteny analysis was performed between M. reevesii (freshwater turtle) and Gopherus evgoodei (terrestrial turtle) genomes. In general, each chromosome of M. reevesii corresponded to one chromosome of Gopherus evgoodei, but some interchromosomal rearrangements occurred between the two species based on the assembled genomes. These interchromosomal rearrangements were further confirmed by mapping of the long-read nanopore data to the assembly. The reconstructed demographic history showed varied effective population size among freshwater, marine and terrestrial turtles. We also discovered expansion of genes related to the innate immune system in M. reevesii that may provide defence against freshwater pathogens. The high-quality genomic sequence provides a valuable genetic resource for further studies of genetics and genome evolution in turtles.

A new species of the Genus Pelodiscus Fitzinger, 1835 (Testudines: Trionychidae) from Huangshan, Anhui, China.

A new species of the soft-shelled turtle genus Pelodiscus is described based on seven specimens from Huangshan, southern Anhui Province, China. The new species, Pelodiscus huangshanensis sp. nov., is distinguished from other species in the genus Pelodiscus by the following characteristics: (1) Small size (maximum carapace length of 101.16 mm and maximum body length of 190 mm); (2) keel high; (3) tiny yellowish-white spots on the throat; (4) no black pinstripes around the eyes; (5) white longitudinal bands on both sides of the neck in juveniles, absent in adults; (6) plastron yellowish-white, and only a dark patch on each side of the armpit; (7) many tubercles on the dorsal surface, but indistinct in the center; and (8) entoplastron ⌒ shaped. The phylogenetic relationships of the species in Pelodiscus were reconstructed using the sequences of cytochrome b (cyt b) and NADH dehydrogenase subunit 4 (ND4) genes. The new species formed a monophyletic clade with strong support. The uncorrected pairwise distances between the new species and other representatives of Pelodiscus ranged from 5.4% to 9.2% for cyt b and 4.1% to 7.6% for ND4. The new species brings the number of species of the genus Pelodiscus to six; five species are distributed in China, with three species endemic to China.

Sperm storage in the oviduct of the Chinese pond turtle Mauremys reevesii depends on oestrogen-based suppression of the TLR2/4 immune pathway.

The long-term storage of spermatozoa in the female reproductive tract is limited by the innate immune system. Oestrogen plays a role in regulating the innate immune system. Thus, exploring the expression of genes in the Toll-like receptor (TLR) 2/4 pathway and oestrogen receptors in the oviduct of Mauremys reevesii could contribute to our understanding of the mechanism of sperm storage. In this study, three parts of the oviduct (isthmus, uterus and vagina) in three mated and unmated female turtles were used to perform immunohistochemistry and real-time quantitative polymerase chain reaction (qPCR). Immunohistochemistry revealed that the TLR2/4 protein was mainly distributed in epithelial tissues and glandular cell membranes, and that TLR2/4 levels in the oviduct were significantly decreased in mated compared with unmated turtles. Real-time qPCR indicated that TLR2/4, myeloid differentiation factor 88 (MyD88), interleukin 1 receptor associated kinase 4 (IRAK4), TNF receptor associated factor 6 (TRAF6), interferon regulatory factor 3 (IRF3) and interleukin 6 (IL6) mRNA expression was significantly higher in the oviduct of unmated than mated turtles, whereas the opposite was true for the expression of oestrogen receptor 1 (ESR1) and progesterone receptor (PGR). These results indicate that when spermatozoa are stored in the oviduct, an increase in oestrogen suppresses the immune response induced by the TLR2/4 pathway so that spermatozoa are not removed as a foreign substance, but stored until fertilisation. The findings of this study are relevant to our understanding of the relationship between sperm storage and the innate immune system in the oviduct of reptiles.

Acrylamide impairs the developmental potential of germinal vesicle oocytes by inducing mitochondrial dysfunction and autophagy/apoptosis in mice.

Background: Acrylamide (ACR), an important endogenous contaminant in carbohydrate-rich foods, has been involved in various negative effects on multiple organ networks, including the reproductive system. Previous studies have reported that ACR affects oocyte quality and fertility. Purpose: This study aimed to explore the toxic effects and regulatory mechanisms of ACR on mouse germinal vesicle (GV) oocytes. Research Design: In this study, adult female mice were exposed to ACR at 10 mg/kg/day/body weight through their drinking water continuously for 4 weeks. Study Sample and Data Analysis: The mitochondrial function, autophagy/apoptosis, and development potential of GV oocytes were investigated. Results: The results showed that ACR reduced the oocyte diameter, sperm-binding ability, parthenogenetic activation and in vitro fertilization (IVF) rate, and development potential of pre-implantation embryos. We also found that ACR exposure disrupted chromatin configuration, mitochondrial distribution, and membrane potential (Δφm) of oocytes. Actin filament expression was significantly reduced in both the membrane and cytoplasm of mouse oocytes. Moreover, ACR exposure increased LC3-positive signals, early apoptosis rate, aberrant ATG3, ATG5, LC3, Beclin1, and mTOR mRNA expression. Conclusions: These results suggest that ACR exposure can affect the developmental potential of GV oocytes by inducing mitochondrial dysfunction, actin filament assembly, and autophagy/apoptosis.

The interaction between Tu-Izumo1 and Tu-JUNO is involved in turtles hybridization.

The specificity of sperm-egg recognition is crucial to species independence, and two proteins (Izumo1 and JUNO) are essential for gamete adhesion/fusion in mammals. However, hybridization, which is very common in turtles, also requires specific recognition of sperm-egg binding proteins. In this study, we discovered that natural selection plays an important role in the codon usage bias of Tu-Izumo1 and Tu-JUNO. Positively selected sites and co-evolutionary analyses between Tu-Izumo1 and Tu-JUNO have been previously reported, and we confirm these results in a larger analysis containing 25 turtle species. We also showed that Tu-JUNO is expressed on the oocyte surface and that Tu-Izumo1 and Tu-JUNO interact with each other directly in different species hybridization combinations. Co-immunization assays revealed that this interaction is evolutionarily conserved in turtles. The results of avidity-based extracellular interaction screening between Tu-Izumo1 and Tu-JUNO for sperm-oocyte binding pairs (both within and across species) likely suggest that the interaction force between Izumo1 and JUNO has a certain correlation in whether the turtles can hybridize. Our results lay a theoretical foundation for the subsequent development of techniques to detect whether different turtle species can interbreed, which would provide the molecular basis for breeding management and species protection of turtles.

Morphological mechanism allowing a parasitic leech, Ozobranchus jantseanus (Rhynchobdellida: Ozobranchidae), to survive in ultra-low temperatures.

Ozobranchus jantseanus is the largest metazoan known to survive in liquid nitrogen without pretreatment to date; however, the mechanism underlying this tolerance remains unclear. In this study, the first analyses of histological and morphological changes in normal, frozen, and dehydrated states were performed. Adults survived after direct placement in liquid nitrogen for 96 h, with a survival rate of approximately 86.7%. The leech could withstand rapid desiccation and its survival rate after rehydration was 100% when its water loss was below about 84.8%. After freezing, desiccation, and ethanol dehydration, the leech immediately formed a hemispherical shape. Particularly during drying, an obvious transparent glass-like substance was observed on surface. Scanning electron microscopy revealed many pores on the surface of the posterior sucker, creating a sponge-like structure, which may help to rapidly expel water, and a hemispherical shape may protect the internal organs by contraction and folding reconstruction in the anterior-posterior direction. A substantial amount of mucopolysaccharides on the surface and acid cells and collagen fibers in the body, all of which contained substantial polysaccharides, may play a key protective role during freezing. Our results indicate that the resistance of leeches to ultra-low temperatures can be explained by cryoprotective dehydration/vitrification strategies. This article has an associated First Person interview with the first author of the paper.

Quantification and evolution of mitochondrial genome rearrangement in Amphibians.

BACKGROUND: Rearrangement is an important topic in the research of amphibian mitochondrial genomes ("mitogenomes" hereafter), whose causes and mechanisms remain enigmatic. Globally examining mitogenome rearrangements and uncovering their characteristics can contribute to a better understanding of mitogenome evolution. RESULTS: Here we systematically investigated mitogenome arrangements of 232 amphibians including four newly sequenced Dicroglossidae mitogenomes. The results showed that our new sequenced mitogenomes all possessed a trnM tandem duplication, which was not exclusive to Dicroglossidae. By merging the same arrangements, the mitogenomes of ~ 80% species belonged to the four major patterns, the major two of which were typical vertebrate arrangement and typical neobatrachian arrangement. Using qMGR for calculating rearrangement frequency (RF) (%), we found that the control region (CR) (RF = 45.04) and trnL2 (RF = 38.79) were the two most frequently rearranged components. Forty-seven point eight percentage of amphibians possessed rearranged mitogenomes including all neobatrachians and their distribution was significantly clustered in the phylogenetic trees (p < 0.001). In addition, we argued that the typical neobatrachian arrangement may have appeared in the Late Jurassic according to possible occurrence time estimation. CONCLUSION: It was the first global census of amphibian mitogenome arrangements from the perspective of quantity statistics, which helped us to systematically understand the type, distribution, frequency and phylogenetic characteristics of these rearrangements.

Comparison of Adult Testis and Ovary MicroRNA Expression Profiles in Reeves' Pond Turtles (Mauremys reevesii) With Temperature-Dependent Sex Determination.

Some differentially expressed genes (DEGs) that encode key enzymes involved in steroidogenic biosynthesis (CYP19A1) and key molecules related to gonadal functions (DMRT1, SOX9, AMH, FOXL2, WNT4, RSPO2, and GDF9) have been identified in adult gonadal RNA-seq studies of Reeves' pond turtle (Mauremys reevesii) with temperature-dependent sex determination (TSD). Gonadal functional maintenance and gametogenesis comprises a highly regulated and coordinated biological process, and increasing evidence indicates that microRNAs (miRNAs) may be involved in this dynamic program. However, it is not clear how the regulatory network comprising miRNAs changes the expression levels of these genes. In this study, miRNA sequencing of adult testis and ovary tissues from M. reevesii detected 25 known and 379 novel miRNAs, where 60 miRNAs were differentially expressed in the testis and ovary. A total of 1,477 target genes based on the differentially expressed miRNAs were predicted, where 221 target genes also exhibited differential expression. To verify the accuracy of the sequencing data, 10 differentially expressed miRNAs were validated by quantitative reverse transcription real-time PCR, and were found to be consistent with the transcriptome sequencing results. Moreover, several miRNA/target gene pairs, i.e., mre-let-7a-5p/mre-let-7e-5p and CYP19A1, mre-miR-200a-3p and DMRT1, mre-miR-101-3p and SOX9, and mre-miR-138-5p and AMH were identified. To explore the regulatory role of miRNAs, we conducted target gene enrichment analysis of the miRNAs and 221 target genes in the regulatory network. The signaling pathways related to gonadal functional maintenance and gametogenesis based on the DEGs and target genes were then compared. Our findings provide crucial information to facilitate further research into the regulatory mechanisms involving miRNAs in turtle species with TSD.

Characterization of deoxyribonucleic methylation and transcript abundance of sex-related genes during tempera ture-dependent sex determination in Mauremys reevesii†.

A number of genes relevant for sex determination have been found in species with temperature-dependent sex determination. Epigenetics play a key role in sex determination, but characterization of deoxyribonucleic acid methylation of sex-related genes on temperature-dependent sex determination remains unclear. Mauremys reevesii is a typical species with temperature-dependent sex determination. In this study, we analyzed the Cytosine Guanine (CpG) methylation status of the proximal promoters, the messenger ribonucleic acid expression patterns and the correlation between methylation and expression levels of Aromatase, Forkhead box protein L2, Doublesex and mab3-related transcription factor 1, sex-determining region on Y chromosome-box 9, and anti-Müllerian hormone, which are key genes in sex determination in other species. We also analyzed the expression level of genes that encode enzymes involved in methylation and demethylation. The expression levels of Aromatase and Forkhead box protein L2 at the female producing temperature were higher than those at the male producing temperature; the expression levels of Doublesex and mab3-related transcription factor 1, sex-determining region on Y chromosome-box 9, and anti-Müllerian hormone were higher at MPT. The expression of some genes involved in methylation and demethylation is significantly different between male producing temperature and female producing temperature. The expression of messenger ribonucleic acid of genes involved in deoxyribonucleic acid methylation and demethylation affected by temperature, together with other factors, may change the methylation level of the regulatory regions of sex-related genes, which may further lead to temperature-specific expression of sex-related genes, and eventually affect the differentiation of the gonads.

Transcriptome sequencing and comparative analysis of adult ovary and testis identify potential gonadal maintenance-related genes in Mauremys reevesii with temperature-dependent sex determination.

Mauremys reevesii is a classical organism with temperature-dependent sex determination (TSD). Gonad development in early life has recently received considerable attention but gonadal maintenance after sex differentiation in turtles with TSD remains a mystery. In this study, we sequenced the transcriptomes for the adult testis and ovary using RNA-seq, and 36,221 transcripts were identified. In total, 1,594 differentially expressed genes (DEGs) were identified where 756 DEGs were upregulated in the testis and 838 DEGs were upregulated in the ovary. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway analysis suggested that the TGF-beta signaling pathway and Hedgehog signaling pathway have important roles in testis maintenance and spermatogenesis, whereas the Hippo signaling pathway and Wnt signaling pathway are likely to participate in ovary maintenance. We determined the existence of antagonistic networks containing significant specific-expressed genes and pathways related to gonadal maintenance and gametogenesis in the adult gonads of M. reevesii. The candidate gene Fibronectin type 3 and ankyrin repeat domains 1 (FANK1) might be involved with the regulation of testis spermatogenesis.

Detecting coevolution of positively selected in turtles sperm-egg fusion proteins.

Physically interacting sperm-egg proteins have been identified using gene-modified animals in some mammal species. Three proteins are essential for sperm-egg binding: Izumo1 on the sperm surface, and JUNO and CD9 on the egg surface. Most proteins linked to reproductive function evolve rapidly among species by positive selection, and have correlated evolutionary rates to compensate for changes on both the sperm and egg. Up to now, interactions between sperm and egg proteins have not been identified in non-mammalian vertebrates, such as turtles that have interspecific hybrids that can produce surviving F1 generations. To explore the potential physical interactions of sperm-egg proteins in turtle species, the coding region of Izumo1, JUNO, and CD9 homologous genes (named Tu-Izumo1, Tu-JUNO, and Tu-CD9) in six turtle species (Mauremys reevesii, M. mutica, M. sinensis, Cistoclemmys flavomarginata, Platysternon megacephalum and Chrysemys picta bellii) were identified, amplified, and sequenced, and tissue-specific expression was analyzed in M. reevesii. We constructed phylogenetic trees and analyzed the signatures of coevolution between sperm-egg protein pairs using MirrorTree Server and linear regression methods. The results showed that Tu-Izumo1, Tu-JUNO, and Tu-CD9 proteins have correlated evolutionary rates, and that the area where Tu-Izumo1 interacts with Tu-JUNO has only one positive selection site in some turtle species. These results suggest there is a potential interaction between Tu-Izumo1 and Tu-JUNO among turtles that can interbreed, and that a significantly lower positive selection in the interaction region may be one of the reasons why turtle hybrids are so common. Further studies are required to uncover Tu-Izumo1, Tu-JUNO and Tu-CD9 protein biological functions during gamete fusion.

Antidepressant effect of helicid in chronic unpredictable mild stress model in rats.

Helicid (4-formylphenyl-ß-D-allopyranoside) is a bioactive constituent of Helicid nilgirica Bedd that has been used in Chinese traditional herbal medicine to treat headache, insomnia, and depression. However, the underlying mechanisms of these effects are unclear. We have now investigated the effect of helicid on depression-related behaviors in rats exposed to chronic unpredictable mild stress (CUMS) and have also explored possible underlying mechanisms that involve neurotrophin expression. After 6 weeks isolation, body weight and sucrose preference were significantly reduced in rats with CUMS-induced depression compared with controls. The CUMS rats also showed significant inhibition of locomotory parameters in open field tests (involving behavioral assays). Helicid significantly regulated levels of corticosterone (CORT), inflammatory cytokines and 5-hydroxytryptamine (5-HT). Helicid also reversed CUMS-induced decreases of 5-HT1A receptor expression and promoted brain derived neurotrophic factor (BDNF) expression in the hippocampus The significant reversal of depressive-like behaviors by helicid is similar to that achieved by fluoxetine. The antidepressive effects are likely attributable to the promotion of hippocampal neurotrophin expression through activation of the serotonergic system. Helicid thus has potential for treating depressive disorders.

miR-21-5p induces cell proliferation by targeting TGFBI in non-small cell lung cancer cells.

The mortality rate of non-small cell lung cancer (NSCLC) remains high worldwide. miR-21-5p plays an important part in many cancer types, including NSCLC. However, the effect of miR-21-5p in NSCLC tumorigenesis remains poorly understood. The present study investigated whether miR-21-5p promoted NSCLC cell proliferation in vitro. In order to study the molecular mechanism by which miR-21-5p contributes to NSCLC progression, three bioinformatics algorithms were used to predict the genes which miR-21-5p targeted. TGFBI was identfieid as a putative direct target in NSCLC cells via the luciferase reporter assay. Furthermore, miR-21-5p downregulated TGFBI protein expression by a post-transcriptional mechanism via western blotting and a reverse transcription-quantitative polymerase chain reaction analysis. Finally, TGFBI exhibited opposing effects to those of miR-21-5p on NSCLC cells, suggesting that miR-21-5p may promote cell proliferation by negative regulation of TGFBI. These results suggest miR-21-5p promote the proliferation of NSCLC cells via inhibiting TGFBI expression.

Single-molecule long-read transcriptome profiling of Platysternon megacephalum mitochondrial genome with gene rearrangement and control region duplication.

Platysternon megacephalum is the sole living representative of the poorly studied turtle lineage Platysternidae. Their mitochondrial genome has been subject to gene rearrangement and control region duplication, resulting in a unique mitochondrial gene order in vertebrates. In this study, we sequenced the first full-length turtle (P. megacephalum) liver transcriptome using single-molecule real-time sequencing to study the transcriptional mechanisms of its mitochondrial genome. ND5 and ND6 anti-sense (ND6AS) forms a single transcript with the same expression in the human mitochondrial genome, but here we demonstrated differential expression of the rearranged ND5 and ND6AS genes in P. megacephalum. And some polycistronic transcripts were also reported in this study. Notably, we detected some novel long non-coding RNAs with alternative polyadenylation from the duplicated control region, and a novel ND6AS transcript composed of a long non-coding sequence, ND6AS, and tRNA-GluAS. These results provide the first description of a mtDNA transcriptome with gene rearrangement and control region duplication. These findings further our understanding of the fundamental concepts of mitochondrial gene transcription and RNA processing, and provide a new insight into the mechanism of transcription regulation of the mitochondrial genome.

miR-24-3p promotes cell migration and proliferation in lung cancer by targeting SOX7.

Lung cancer (LC) is one of the leading causes of cancer-related death in the world. miR-24-3p plays critical roles in many cancer types, including LC. In this study, we first investigated whether miR-24-3p promoted LC cell migration and proliferation in vitro. We used three bioinformatics algorithms to predict the miR-24-3p target gene to study the molecular mechanism by which miR-24-3p contributes to LC progression. Then, we used the luciferase reporter assay to identify whether SOX7 was a direct target of miR-24-3p. Moreover, Western blotting and a quantitative real time-polymerase chain reaction analysis showed that miR-24-3p downregulated SOX7 protein expression by a post-transcriptional mechanism. Finally, we determined that SOX7 had opposing effects to those of miR-24-3p on LC cell proliferation and migration, suggesting that miR-24-3p promotes cell proliferation and migration by directly targeting SOX7. Furthermore, miR-24-3p accelerated tumor growth in xenograft mice by targeting SOX7. These results provide the first clue that miR-24-3p could play a role as an oncomiR in LC by regulating SOX7.

[Effect of exercise on adiponectin in aged obese rats].

OBJECTIVE: To explore effects of exercise on the expression of adiponectin mRNA and protein in visceral adipose tissue, plasma adiponectin concentration, and insulin resistance of aged obese rats. METHODS: Male SD rats age to 21 days old were fed with high-fat diet (fat percentage was 36.3% to 40.0%) for three stages of adolescence, maturity and old age to establish elderly obesity rats model. When the rats aged to 60 weeks old, natural growing elderly rats were randomly divided into control group (C) and aged exercise group (AE), n=6; elderly obesity rats were randomly divided into obesity control group (OC) and obesity exercise group (OE), n=6. The treadmill grade was 0°, the exercise speed and time were 15 m/min×15 min, 4 groups each time, between consecutive groups the rats had 5 minutes rest, the rats were exercised for 60 minutes every day, five days a week, continuous exercise for 8 weeks. Then, the expressions of adiponectin mRNA and protein in visceral adipose tissue were determined. The concentrations of blood glucose, plasma adiponectin and insulin were measured. Insulin resistance was calculated. RESULTS: Comparison with control group, the expressions of adiponectin mRNA and protein were obviously decreased, the concentration of blood glucose and insulin resistance were significantly increased in obesity control group, while the expressions of adiponectin mRNA and protein were obviously increased. Comparison with obesity control group, the expressions of adiponectin mRNA and protein, the concentration of plasma adiponectin were obviously increased, the concentration of blood glucose and insulin resistance were significantly decreased in obesity exercise group. CONCLUSIONS: Adiponectin mRNA and protein expression in visceral adipose tissue is decreased and accompanied by high blood glucose and insulin resistance in elderly obesity rats. Exercise can increase the adiponectin mRNA and protein expression in visceral adipose tissue, elevate levels of plasma adiponectin, and decrease the level of blood glucose and insulin resistance in elderly obesity rats.

The complete mitochondrial genome of the Cyclemys fusca (Chelonia: Geoemydidae).

The complete mitochondrial genome (mitogenome) of Cyclemys fusca was obtained and characterized in this study. The circular molecule is 16,491 bp in length and contained 13 protein-coding genes (PCGs), two ribosomal RNA (rRNA) genes, 22 transfer RNA (tRNA) genes, and one non-coding region (control region). Its gene arrangement type is identical to the type of most vertebrate. All protein-coding genes initiate with ATG as start codon, except for COI started with GTG. Interestingly, COI and ND6 end up with AGG. The complete mitogenome of C. fusca provides the basic data to research molecular systematics of Geoemydidea.