Differentiation of subspecies of asiatic striped squirrels (Tamiops swinhoei) (Milne-Edwards) (Rodentia : Sciuridae) in China with description of a new subspecies

Based on the pelage characteristics and results of multivariate and univariate analyses, a new subspecies is described in this study, and a taxonomic revision of Tamiops swinhoei from China is presented. In total, 123 specimens of Tamiops swinhoei were in

Sexual Behavior Modulates Contextual Fear Memory Through Dopamine D1/D5 Receptors

Traumatic events always lead to aversive emotional memory, i.e., fear memory. In contrast, positive events in daily life such as sex experiences seem to reduce aversive memory after aversive events. Thus, we hypothesized that post-traumatic pleasurable ex

SEXUAL-BEHAVIOR OF TIBETAN MACAQUES AT MT EMEI, CHINA

Data on sexual behavior were collected in six groups of semi-commensal Macaca thibetana along the trail on the slope habitat between 1987 and 1989. Ignoring the common items such as mounting, presenting etc., 20 categories of sexual behavior were described. Most of the descriptions were likely to have enlarged the behavior repertoire reported in macaques, showing a great complexity of sociosexual interactions under the principally natural condition. A great diversity of grouping appeared in the mating season. The copulatory pattern was found to be the serial type contrary to previous speculation, and the mount-to-ejaculation ratio was higher in the central subgroup, as compared with the far-peripheral adult subgroup (FAS) with less male and female rivals. An age-class subdivision of sexually active males made it possible to show that the young adult male immigrants were the most active class in sexual activity. Subgrouping form FAS was a ''space-segregation'' tactic of mating for the losers of both sexes in the competition. Some parameters of copulation were also documented.

THE ORIGIN AND GENETIC DIFFERENTIATION OF NATIVE BREEDS OF PIGS IN SOUTHWEST CHINA - AN APPROACH FROM MITOCHONDRIAL-DNA POLYMORPHISM

Mitochondrial DNA (mtDNA) of six breeds of native domestic pigs from Yunnan province, southwest China, and two wild boars obtained from Sichuan, China, and Vietnam was analyzed using 20 restriction endonucleases that recognize six nucleotides. Restriction maps were made by double-digestion methods and polymorphic sites were located on the map. According to their mtDNA restriction types, all the breeds were classified into six groups. Genetic distances among groups were calculated to define their phylogenetic relationships. The relationship between the Sichuan wild boar and domestic pigs is close, while the Vietnamese wild boar is relatively far from them, so the domestic pigs in southwest China are likely to have originated from a wild pig which distributed in west China. We compare our results with previous reports in literature and discuss the relationship among Chinese pigs, Japanese pigs, and European pigs. The mtDNA cleavage pattern of the Mingguang pig digested by EcoRV was identical to that of Duroc; mutations at the EcoRI site, detected in the mtDNA of two Dahe pigs, are the same as in the Vietnamese wild boar, suggesting that mutational hot spots exist in the mtDNA of pigs.

SEXUAL DIMORPHISM IN THE SNUB-NOSED LANGURS (COLOBINAE, RHINOPITHECUS)

Sexual dimorphism in the dentition and skeleton of the four extant species of snub-nosed langurs, Rhinopithecus (R.) bieti, R. (R.) brelichi, R. (R.) roxellana and R. (Presbytiscus) avunculus, was studied. The species shared a similar general pattern of sexual dimorphism, but were found to differ in respects that appear to reflect the influence of disparate socioecological and environmental factors. All the species showed marked canine dimorphism, but the very high degree of canine dimorphism in R. bieti appeared to be due to the intensity of intermale competition for mates during a temporally restricted breeding season, and possibly also to the intensity of competition between males for other resources during other times of the year. Sexual dimorphism in the postcranial skeleton of Rhinopithecus species was also most pronounced in R. bieti and may be related to the relatively higher frequency of terrestrial locomotion in males of the species. (C) 1995 Wiley-Liss, Inc.

Sexual differences in vigilance of paired Ruddy Shelduck in winter

The effect of distance between members of pairs of the Ruddy Shelduck (Tadorna ferruginea) during vigilance behavior was studied during winter at Lijiang Lashihai Lake Reserve, southwest China. The distance between the paired birds while feeding was grouped into three categories: <1 m, 1-3 to and >3 m. Nearly 90% of the distances recorded between paired males and females were within three meters. The degree of vigilance increased with distance apart for females, but not for males. The scanning rate of males was significantly, higher than that of females at <1 m and at 1-3 m respectively, but no significant difference occurred when the distance between them was >3 m. These results are discussed in relation to mate competition and wintering strategy; it is suggested that staving close together is the optimal strategy for members of Ruddy Shelduck pairs.

Sexual behavior in a one-male unit of Rhinopithecus bieti in captivity

Data regarding the sexual behavior of black-and-white snub-nosed monkeys (Rhinopithecus bieti) were collected in 1998 in a one-male unit in captivity by all-occurrences sampling during the mating season. Before the present study, little was known about the sexual behavior of this species. This study showed that female solicitation is mainly expressed as "prostration plus glancing laterally" (PG) or "sitting plus head moving up and down" (HM), and male solicitation is exhibited by the "grunt bared-teeth display." The mount-to-ejaculation ratio was 5.2 on average, and single-mount ejaculations (SMEs) were observed in only 4.4% of mounts on days with at least one ejaculation. Therefore, the main copulatory pattern of this species is multiple-mount ejaculation (MME). Females initiated 72% of 18 ejaculatory mounts. Females initiated more ejaculatory mounts than non-ejaculatory ones. In general, the patterns of sexual behavior in this species are similar to those reported for other Colobines. (C) 2004 Wiley-Liss, Inc.

Evolutionary Conservation of Dazl Genomic Organization and its Continuous and Dynamic Distribution Throughout Germline Development in Gynogenetic Gibel Carp

To investigate germline development and germ cell specification, we identified a Dazl homolog (CagDazl) from gynogenetic gibel carp (Carassius auratus gibelio). Its cDNA sequence and BAC clone sequence analyses revealed the genomic organization conservation and conserved synteny of the Dazl family members and their neighborhood genes among vertebrates, especially in fish. Moreover, a polyclonal antibody specific to CagDazl was produced and used to examine its expression and distribution throughout germline development at protein level. Firstly, ovary-specific expression pattern of CagDazl was confirmed in adult tissues by RT-PCR and Western blot. In addition, in situ hybridization and immunofluorescence localization demonstrated its specific expression in germ cells, and both its transcript and protein were localized to germ plasm. Then, co-localization of CagDazl and mitochondrial cloud was found, confirming that CagDazl transcript and its protein are germ plasm component and move via METRO pathway during oogenesis. Furthermore, the CagDazl is abundant and continuous throughout germline development and germ cell specification including primordial germ cell (PGC) formation, oogonium differentiation, oocyte development, and embryogenesis, and the dynamic distribution occurs at different development stages. The data suggest that maternal CagDazl might play an important role in gibel carp PGC formation. Therefore, CagDazl is a useful and specific marker for tracing germ plasm and germ cell development in the gynogenetic gibel carp. In addition, in comparison with previous studies in sexual reproduction species, the continuous and dynamic distribution of CagDazl protein in the germ plasm throughout the life cycle seems to have significant implication in sex evolution of vertebrates. J. Exp. Zool. (Mol. Deu. Euol.) 312B:855-871, 2009. (C) 2009 Wiley-Liss, Inc.

Molecular and expression characterization of two somatostatin genes in the Chinese sturgeon, Acipenser sinensis

Chinese sturgeon (Acipenser sinensis) is a rare and endangered species and also an important resource for the sturgeon aquaculture industry. SMART cDNA was synthesized from the hypothalamus of Chinese sturgeon, and the full-length cDNAs of two somatostatin (SS) genes were cloned and sequenced. The first cDNA (AsSS1) encodes a 116-amino acid protein that contains the SS14 sequence at its C-terminal extremity. AsSS1 shows high identity to that of human and other vertebrates. The second cDNA (AsSS2) encodes a 111-amino acid protein that contains the somatostatin variant [Pro(2)]-SS14 at its C-terminal extremity. Both the two SS mRNAs were expressed in brain and pituitary with different mRNA levels. But in peripheral tissues, AsSS2 was more widely distributed than AsSS1. High mRNA levels of AsSS2 were found in liver, kidney and heart, while low mRNA levels of AsSS2 were also detected in ovary. Throughout embryogenesis and early larval development only AsSS2 mRNAs were detected. Furthermore, in the hypothalamus of one to five year-old Chinese sturgeon, AsSS2 but not AsSS1 maintained stable expression. The mRNA distribution suggests that the Chinese sturgeon AsSS2 products play important physiological functions in adult fish as well as in cell growth and organ differentiation in embryo and larva development. (C) 2009 Elsevier Inc. All rights reserved.

Population genetic structure and geographical differentiation of the Chinese catfish Hemibagrus macropterus (Siluriformes, Bagridae): Evidence for altered drainage patterns

National Natural Science Foundation of China (NSFC) [2007CB411600, 30530120]