Supernumerary chromosomes, mosaicism, and dynamics in two populations of Eastern-Asian wood mouse (Apodemus peninsulae, Rodentia) from Primorski? Krai at various seasons of the year]

Karyotypes of 47 individuals of the wood mice Apodemus peninsulae from two reserves in Primorskii krai (Kedrovaya Pad' and Ussuriiskii) were studied during spring, summer, and autumn. In each population, variation in the number of B-chromosomes (2n = 48 + 0-5B) as well as the intratissue mosaicism determined by variation of the number, size and morphology of supernumerary chromosomes were described. Animals that have one dotlike B-chromosome were first described in both populations as rare variants. Individuals that have bone-marrow cell clones with two or three B-chromosomes were found to be predominant in the populations of Primorskii krai. The number of clones varied from one to three per animal. The frequency of mosaics showed seasonal variation. In the population of the Ussuriiskii reserve, a sharp increase in the frequency of animals with a stable karyotype was detected in autumn, at the phase of increased numbers. The variation for mosaicism was suggested to correlate with the population numbers in mice and to indicate the genetic differences between generations of the population.     

甘肃仓鼠的核型与分类地位

利用常规核型和带型技术对分布于陕西宁陕的甘肃仓鼠进行了研究, 其核型为2n = 24 = 16 m + 4 sm +2st + 2t 。由于没有得到雄性个体, 所以很难确定性染色体。部分染色体有着丝粒C - 带, 有1 对亚端染色体长臂具较大近着丝粒异染色质带, 暂定为X染色体。3 对染色体上有NORs。与已有报道的大仓鼠染色体比较, 两者有显著差异。因此从染色体特征上看, 将甘肃仓鼠作为大仓鼠的亚种是不合适的。     

大仓鼠的核型与B染色体研究

采用骨髓细胞染色体制片法,对分布于山东济南、泰山、东北长白山和陕西西安的大仓鼠的染色体组型、Ｇ－带、Ｃ－带和银染核型进行了分析研究。济南、西安和长白山的标本的二倍体数目和核型相似,２ｎ＝２８,２２ｔ＋４ｍ＋ＸＹ（ｓｔ,ｍ）。泰山标本的二倍体数目为２ｎ＝２８～２９,即在６７５％的中期相中多出了一条形态最小的端着丝粒染色体,这条染色体为Ｂ染色体,可能起源于Ｘ染色体。泰山标本的Ａ染色体组与上述３地标本相同。４地标本的Ｇ－带、Ｃ－带和银染核型相似。除Ｂ染色体外,每个端着丝粒染色体都具有着丝粒异染色质,ＡｇＮＯＲｓ较恒定地出现在Ｎｏｓ２,４,８,９,１３染色体上。也就是说大仓鼠的Ｂ染色体为Ｃ－带阴性,不携带核仁组织者。这种Ｂ染色体Ｃ－带阴性的特征在赤狐、黑家鼠和大林姬鼠朝鲜亚种中亦有报道。     

Diversity of the mitochondrial DNA cytochrome b gene of the field mouse Apodemus agrarius Pallas, 1771 in the south of the Russian Far East

We studied the variability of a fragment of the cytochrome b gene and the corresponding amino acid sequence of the field mouse Apodemus agrarius (Pallas, 1771) in the South of Primorskii krai (Far East of Russia). A significant polymorphism of these traits was detected. High indices of molecular diversity were obtained. The topology of the phylogenetic tree and the median networks suggest that the population of field mice in the south of Primorskii krai originated from three maternal lines. It was noted that clustering of haplotypes on a territorial basis is absent, and the field mouse population in southern Primorskii krai can be considered as one of the key points in maintaining a high genetic diversity of the species.     

Coat color mutation frequencies in domestic cat populations of Primorskii krai, Russia

The frequencies of mutant coat color genes have been estimated in the cat populations of five settlements in Primorskii krai, Russia: two cities (Partizansk and Spassk-Dal'nii), a town (Khorol'), and two villages (Dmitrievka and Brovnichi). The genetic profiles of these populations have been found to be relatively homogenous and to correspond of the cat population of the city of Vladivostok studied earlier. No considerable differences in gene frequencies have been found between urban and rural cat populations. The data suggest a common origin of all domestic cat populations of Primorskii krai.     

Genetic diversity and phylogenetic relationships of the Manchurian zokor <Emphasis Type="Italic">Myospalax psilurus</Emphasis> (Rodentia,Muridae) according to RAPD-PCR analysis

The population structuring and low genetic diversity of the Manchurian zokor Myospalax psilurus Milne-Edwards, 1874, an East Asian endemic included in the Red List of Russia, were demonstrated. Two separate geographical groups differing in the level of their genetic diversity were found on the territory of the Primorskii krai. The subpopulation located closest to the main area of this species was determined as ancestral. A subspecies differentiation of the Primorskii krai and Transbaikal M. psilurus populations was shown, as was the monophyletic origin of M. psilurus and its high divergence from M. aspalax. The animals from northern localities are recommended for reintroduction in nature under species recovery programs in Primorskii krai.     

Mitotic and meiotic chromosomes of Mabuya (Scincidae: Reptilia)

A study was carried out on conventionally stained mitotic and meiotic chromosomes of two species of lizards of the Scincidae: Mabuya caissara and M. macrorhyncha.On the basis of morphological, numerical and metric data, the chromosomes were divided into three groups: two groups of macrochromosomes (A and B) and one of microchromosomes (C). The karyotypes of males and females of both species showed 2n=32 and FN=50 and no differences were detected between the species.     

Experimental fascioliasis in the rat-like hamster,Tscherskia triton,and other rodent hosts

Experimental infection with Fasciola hepatica and parthenogenetic Fasciola sp. in laboratory animals have been conducted in rats and rabbits. Inoculation of less than 5 metacercariae into rat-like hamsters, Tscherskia triton, is sufficient to establish Fasciola infections. The prepatent period of F. hepatica and the parthenogenetic Fasciola sp. in T. triton was shorter than that in rats and rabbits, suggesting that T. triton is a suitable experimental model for these flukes. In contrast, F. gigantica infection in T. triton did not yield adult flukes; T. triton, is therefore, considered to be an unsuitable host for F. gigantica. The cotton rat, Sigmodon hispidus, was an unsuitable host for the parthenogenetic Fasciola sp.     

复方避孕药物(EP-1) 对雄性大仓鼠繁殖器官的影响

鉴于传统化学灭杀方法存在的不足和缺陷,各国都在致力于研究无公害、可持续的鼠害防治技术与策略,其中不育控制是当前研究的一个热点：近年来我国在鼠类不育控制方面也开展了一些研究（张知彬等,1997a,1997b,2001;Shi et a1．．2002;Li et a1．,2006）。     

The rat-like hamster,Tscherskia triton,as a host for the parthenogenetic liver fluke Fasciola sp

Metacercariae of parthenogenetic Fasciola sp. triploid were inoculated into the rat-like hamster Tscherskia triton. Flukes at various stages of growth were found in the bile ducts of all 8 (50%) animals that survived from 42 to 90 days. The body length to width ratio ranged from 1.8 to 2.9, and flukes with the highest ratio were passed 68 days after inoculation. Our results indicate that T. triton is a suitable host for experimental infection when induced by a small number of metacercariae (less than 5) of Fasciola sp.     

The natural host range of hantaviruses and their reservoir potential in the dynamics of the epizootic process within the ecosystems of Primorskii Krai

Dynamics of the reservoir potential (RP) and its index (IRP) in rodents inhabiting Primorskii krai and carriers of hantaviruses have been studied. The long-term annual average IRP in the genus Apodemus equals 0.83. In A. peninsulae, the IRP has turned out to be two times higher than that in A. agrarius (t = 2.636; n = 18; p = 0.017). The prognostic markers of a possible outbreak of epidemic disease caused by hantaviruses in Primorskii krai are discussed.     

The first data on the biology and distribution of the Japanese fringed sculpin <Emphasis Type="Italic">Porocottus japonicus</Emphasis> Schmidt, 1935 (Scorpaeniformes: Cottidae) in the northwestern Sea of Japan

The Japanese fringed sculpin Porocottus japonicus Schmidt has been found in the Rynda (44°48′03″ N, 136°23′24″ E) and Vladimira (43°52′36″ N, 135°29′30″ E) (Sea of Japan, Primorskii krai) bays for the first time. This species was formerly known only from the northern Tatar Strait and Aniva Bay. In Primorskii krai, P. japonicus inhabits macrophyte beds in shallow sublittoral waters. It reaches a length of 112 mm during its lifespan of approximately 4 years. Spawning occurs in the winter. The species preys predominantly on polychaetes (82.3% of the food weight).     

New occurrence of B chromosomes in Partamonahelleri (Friese, 1900) (Hymenoptera, Meliponini)

Cytogenetic analyses of the stingless bee Partamona helleri collected in the state of Bahia, Northeast Brazil revealed the chromosome numbers n = 18 in the haploid males and 2n = 35 in the diploid females. All karyotypes displayed one large acrocentric B chromosome, which differs from the minute B chromosomes previously described in the populations from southeastern Brazil. Giemsa staining, C-banding and DAPI/CMA(3) fluorochrome staining also revealed a remarkable interpopulational divergence regarding both the regular karyotype and the B chromosomes. The B chromosomes found in the samples from Jequié, Bahia, were entirely heterochromatic, while those found in Cravolandia, Bahia, displayed a euchromatic portion at the telomeric end of the long arm. CMA (3) labeling sites varied from seven to eight between the two localities in Bahia, due to the presence of an extra GC-rich block in the karyotype of the samples from Jequié. This is the first report of a large B chromosome in P. helleri and reveals the occurrence of a geographic differentiation within this species.     

Karyotype, Ag-NOR, CMA3 and SEM studies in a fish (Mystus tengara, Bagridae) with indication of female heterogamety

Somatic karyotypes in M. tengara contained 54 chromosomes, comprising 26 homomorphic pairs in both sexes and one pair of heteromorphic nature in female (one big submetacentric and one small subtelocentric chromosomes), while in males this pair was homomorphic (with two big sub-metacentric chromosomes). The Nucleolus Organizer Regions (NORs) were located at one arm of the suspected sex elements in both sexes, while another pair of metacentric chromosomes (No.7) also showed Ag-positive arm. The CMA3 technique revealed relatively bright fluorescing zones in the regions of chromosomes that showed Ag-positive staining, revealing thereby the preponderance of GC-rich active sites of rRNA genes in NORs. SEM studies revealed clear heteromorphism to exist in the elements suspected as sex chromosomes in females.     

The Karyotype Analysis of Triticum monococcum

The comparisom of karyotypes between 10 different materials of T. monococcum and T. boeoticum was carried out using flame-drying slides prepared by smear method. Cytological observation shows that their karyotypes appear very similar and may belong to the genome A of wheat. They both are found to possess 7 pairs of chromosomes (2n=14), i.e. 5 pairs of metacentric and 2 pairs of submetacentric chromosomes. All the No. 5 chromosomes have a satellite.     

Occurrence of B chromosomes in Tetragonisca Latreille, 1811 (Hymenoptera, Apidae, Meliponini): A new contribution to the cytotaxonomy of the genus

Tetragonisca angustula and Tetragonisca fiebrigi have recently been listed as valid species. This study aimed to cytogenetically investigate both species, emphasizing the new registry of B chromosomes in the tribe Meliponini. We analyzed colonies of T. angustula and T. fiebrigi collected at Tangará da Serra, Mato Grosso, Brazil, through conventional Giemsa staining, C-banding, and base-specific fluorochrome staining (CMA(3)/DAPI). T. angustula showed 2n = 34 chromosomes in females and n = 17 in males, with karyotype formula 2K = 34A(M). T. fiebrigi showed numeric variation, with chromosome number varying from 2n = 34 to 2n = 36 in females and from n = 17 to n = 18 in males, with karyotype formula 2K = 32A(M)+2A(Mc) and 2K = 32A(M)+2A(Mc) + 1 or 2 B-chromosomes. The B chromosomes are heterochromatic. In T. fiebrigi, the CMA(3)/DAPI staining revealed four chromosomes with a CMA(3) positive band. All individuals from the same colony showed the same number of B chromosomes. T. angustula and T. fiebrigi showed karyotype divergence, principally due to the presence of B chromosomes, which are found only in T. fiebrigi. Our data corroborate the status of valid species for both T. angustula and T. fiebrigi, as recently proposed.     

雄性大仓鼠体重对其斗殴行为及社会等级的作用

在实验室条件下测定雄性大仓鼠体重对社会等级和斗殴行为的作用模式,检验体重对雄性大仓鼠社会等级及斗殴行为序列具有重要影响的假设。本实验以16只成年雄性大仓鼠为目标个体,采用等级内部的线性概率、组内循环三元组数量（d）和优势等级的线性度（K）,排列个体的社会等级序位。研究结果表明,雄性大仓鼠可形成近似线性的优势等级,体重与个体的优势等级,攻击行为和胁腺标记行为均呈显著的正相关关系,与防御行为和攻击潜伏期存在显著的负相关关系。说明独居性物种大仓鼠雄体间可形成优势等级关系,体重对此关系具有重要的作用。     

Sexual selection in the monogamous barn swallow (Hirundo rustica). II. Mechanisms of sexual selection

Mechanisms of sexual selection in the monogamous, sexually dimorphic barn swallow (Hirundo rustica) were studied during a seven-year period. First, the sex ratio of reproducing adults was male-biased, and mated males had significantly longer tail ornaments than unmated males. Secondly, some of the unmated individuals later committed infanticide and became mated with the mother of the killed brood. Fathers of killed broods had significantly shorter tails than other males, and there was a tendency for infanticidal males to have longer tail ornaments than other unmated males. Thirdly, long-tailed male barn swallows were more successful in acquiring extra-pair copulations than other males, and females involved in extra-pair copulations, as compared to females not involved in such copulations, had mates with shorter tail ornaments. Fourthly, male barn swallows having long tails as compared to short-tailed males acquired mates in better body condition. Females mated to long-tailed males reproduced earlier, laid more eggs and were more likely to have two clutches than were females mated to short-tailed males. Finally, females mated to long-tailed males put more effort into reproduction than did other females, as evidenced by their relatively larger contribution to feeding of offspring. Thus, at least five different components of sexual selection affected male reproductive success. Selection arising from differential success during extra-pair copulations, differential reproductive success and differential male reproductive effort thus accounted for most of the selection on tail ornaments in male barn swallows.     

A karyological study of the spirurid nematode Mastophorus muris (Nematoda: Spirocercidae)

The karyotype of Mastophorus muris (Gmelin, 1790) comprises four pairs of small autosomal chromosomes and two larger sex X chromosomes in females or one X chromosome in males (2n = 8 + XX/XO). All pairs of chromosomes possess rather uniform morphology without distinct primary or secondary constrictions. No heterochromatin bands were found by C-banding analysis. The absolute chromosome length ranges from 4.02 to 2.24 microns. The mean total length of the haploid complement is 14.34 microns. The course of gametogenesis represents a typical pattern common in the order Spirurida. The recently available karyotypes of spirurid nematodes have been reviewed.     

Genetic studies of house mice from the hybrid area of the Primorskii Region

Cytogenetic and allozyme differentiation of house mice Mus musculus L. was studied in 21 samples of Primorskii krai (region) from 1984 to 1998. The use of Q-H- and C-banding made it possible to reveal a high variation in the content and distribution of pericentromeric heterochromatin and high frequencies of marker autosomes 5, 7, 10, 12, 15, and 17-19 in the karyotypes of mice from some samples. The presence of marker alleles that are typical of the subspecies groups castaneus and musculus was shown for protein loci Idh, Sod-1, Aat-1, and Hbb. The data obtained indicate that the fauna of house mice of Primorye is characterized by subspecific mosaicism and hybrid origin. Apparently, subspecies M. m. castaneus, M. musculus ssp., M. M. homourus, and M. m. gansuensis contributed, to different degrees, to the formation of this fauna.