蒙古狼线粒体基因组序列分析及其系统发育地位

应用Long-PCR和克隆测序法得到蒙古狼(Canis lupus chanco)线粒体基因组全序列,结合GenBank中现有犬科动物线粒体基因组数据,应用最大简约法(MP)、最大似然法(ML)和Bayesian分析法对蒙古狼的系统发育地位进行了探讨。结果如下:蒙古狼线粒体基因组全长16709bp,包含13个蛋白质编码基因、22个tRNA基因、2个rRNA基因和1个非编码区。序列碱基的组成存在明显的A-T偏好性。tRNA基因中除tRNA-Ser(AGY)缺少双氢尿嘧啶(DHU)臂以外,其余均能折叠成典型的三叶草二级结构。大多数蛋白质编码基因的起始和终止密码子与犬科动物有报道相同,COXⅡ基因的起始密码子为ATA,与其他犬科动物不同。基于12S rRNA+16S rRNA+H链上的12个蛋白质编码基因的联合数据的系统发育分析发现,在已报道的狼亚种数据中,西藏狼(Canis lupus laniger)的分化时间最早,其次为阿拉伯狼(Canis lupus arabs),蒙古狼与欧亚狼(Canis lupuslupus)的系统发育地位最为接近。     

An investigation of the products of 53 gene loci in three species of wild Canidae: Canis lupus,Canis latrans,and Canis familiaris

This article describes an investigation of inter- and intraspecific variation in three small populations of wild Canidae-wolf, coyote, and dingo. The products of 53 gene loci were examined. Very little interspecies variation was observed, but the level of intraspecific variation was compatible with that found in man.     

Babesia Canis Canis, Babesia Canis Vogeli, Babesia Canis Rossi: Differentiation of the Three Subspecies By A Restriction Fragment Length Polymorphism Analysis On Amplified Small Subunit Ribosomal Rna Genes

The parasites Babesia canis and Babesia gibsoni (phylum Apicomplexa) are responsible for canine babesiosis throughout the world. Babesia canis was previously described as a group of three biologically different subspecies, namely B. canis canis, B. canis vogeli, and B. canis rossi. We report partial sequences of small subunit ribosomal RNA gene (ssu-rDNA) of each subspecies amplified in vitro with primers derived from a semi-conserved region of the ssu-rDNA genes in other Babesia species. The polymerase chain reaction combined with a restriction fragment length polymorphism analysis, using HinfI and TaqI restriction enzymes, confirmed the separation of B. canis into three subspecies. These sequences were compared with previously published sequences of other Babesia species. A phylogenetic approach showed that the three subspecies of B. canis belong to the clade of Babesia species sensu stricto where B. canis canis clusters with B. canis rossi whereas B. canis vogeli might form a monophyletic group with the cluster B. divergens and B. odocoilei. Our results show that the three subspecies of B. canis can readily be differentiated at the molecular level and suggest that they might be considered as true species.     

A Comparison of the Sensory Development of Wolves (Canis lupus lupus) and Dogs (Canis lupus familiaris)

Little is known about the development of the sensory systems of wolves. The timing of sensory development in wolves is usually extrapolated from studies on dogs, since they are members of the same species. However, early developmental differences between these two subspecies have already been identified. For example, wolves tend to approach and investigate objects in their environment 2 wk before dogs. These changes in developmental timing may play an important role in the behavioral differences between adult wolves and dogs. The purpose of this study is to compare the development of the sensory systems in wolves and dogs. Responses of seven wolf pups and 43 dog pups to familiar and novel olfactory, auditory, and visual stimuli were tested weekly from 2–7 wk of age. Eleven wolf pups were also observed for orientation towards auditory and visual stimuli during 2‐h sessions, 5 d a week, from 2–8 wk of age. These observations were supplemented by the daily records of caretakers. The results suggest that wolves and dogs both develop olfaction by 2 wk, audition by 4 wk, and vision by 6 wk on average, despite the 2‐wk shift in their ability to explore. This means that when wolves begin to explore at 2 wk, they are blind and deaf, and must rely primarily on their sense of smell. Thus, there is a significant alteration of how these subspecies experience their environment during the critical period of socialization. These findings lead to an alternative explanation for the difference in dogs' and wolves' abilities to form interspecies social attachments, such as those with humans.     

Genetics and conservation of wolves Canis lupus in Europe

• 1 The wolf Canis lupus, the most widespread of the four species of large carnivores in Europe, after centuries of population decline and eradication, is now recovering in many countries. Wolves contribute to regulating prey–predator dynamics and interact with human activities, mainly livestock farming and ungulate hunting. Although wolves are protected in most European countries, illegal or incidental killing is widespread.
• 2 Wolf populations do not show any apparent phylogeographic structuring worldwide. Molecular and morphological studies of historical samples showed evidence of wolf ecomorph extinctions, coinciding with the great Pleistocene faunal turnover.
• 3 Extant populations show recurrent long‐range dispersal during cycles of expansion and recolonization. Demographically stable populations, in contrast, seem to be characterized by very limited gene flow.
• 4 Despite the potential for dispersal and ecological flexibility, landscape genetic approaches have demonstrated the existence of genetically distinct wolf populations, which originated through habitat and prey specializations.
• 5 Small isolated wolf populations may suffer from inbreeding depression, although selection for heterozygotes and the rescue effect can foster rapid population recovery. Population structure and dynamics is efficiently monitored by non‐invasive genetic methods, which are also useful to identify wolf × dogCanis lupus familiaris hybridization.
• 6 Despite technical advances and a better knowledge of wolf biology, wolf conservation is largely dependent on humans, and on the solution of conflicts with stakeholders.

     

Using faecal DNA sampling and GIS to monitor hybridization between red wolves (Canis rufus) and coyotes (Canis latrans)

The US Fish and Wildlife Service's (USFWS) Red Wolf Recovery Program recognizes hybridization with coyotes as the primary threat to red wolf recovery. Efforts to curb or stop hybridization are hampered in two ways. First, hybrid individuals are difficult to identify based solely on morphology. Second, managers need to effectively search 6000 km(2) for the presence of coyotes and hybrids. We develop a noninvasive method to screen large geographical areas for coyotes and hybrids with maternal coyote ancestry by combining mitochondrial DNA sequence analysis of faeces (scat) and geographic information system (GIS) technology. This method was implemented on the Alligator River National Wildlife Refuge (1000 km(2)) in northeastern North Carolina. A total of 956 scats were collected in the spring of 2000 and 2001 and global positioning system (GPS) coordinates were recorded. Seventy-five percent of the scats were assigned to species and five coyote/hybrid scats were detected. Placement of scat location coordinates on a map of the experimental population area revealed that four of the coyote/hybrid scats were detected within the home ranges of sterilized hybrids. The other coyote/hybrid scat indicated the presence of a previously unknown individual. We suggest this method be expanded to include more of the experimental population area and be optimized for use with nuclear markers to improve detection of hybrid and back-crossed individuals.     

Multiple Character Analysis of Canis lupus, latrans, and familiaris, With a Discussion of the Relationships of Canis niger

A multiple character analysis was undertaken of a broadly representativesample of three species:Canis lupus (wolf), C. latrans (coyote),and C. familiaris (dog). These species are clearly and significantlydistinguished by the technique of linear discrimination. Theanalysis provides a basis for the identification of skulls notobviously distinguishable by size or other diagnostic characters. Early populations of Canis n. niger and C. n. gregoryi (redwolf) are compared with the three species above and are foundto form a cluster with lupus and to be sharply distinct fromthe other two species. Additional comparisons show that whilelupus lycaon and niger both overlap with lupus, they are distinctfrom each other. This entire cluster is quite distinct fromlatrans, with niger being the farthest removed. A sample populationof C. n. gregoiyi, from the edge of the extending range of C.latrans, was examined and found to show too great a range ofvariation to be attributed to a single species.     

Morphologische Unterscheidungsmerkmale zwischen Wolfs-(Canis lupus L.) und Hundeschädel (Canis familiaris L.)

European Journal of Wildlife Research - Durch Vergleich von 145 Wolfsschädeln mit 165 Schädeln großer Hunde fand der Verfasser sieben Merkmale am Schädel und ein Merkmal am...     

Size‐assortative choice and mate availability influences hybridization between red wolves (Canis rufus) and coyotes (Canis latrans)

Anthropogenic hybridization of historically isolated taxa has become a primary conservation challenge for many imperiled species. Indeed, hybridization between red wolves (Canis rufus) and coyotes (Canis latrans) poses a significant challenge to red wolf recovery. We considered seven hypotheses to assess factors influencing hybridization between red wolves and coyotes via pair‐bonding between the two species. Because long‐term monogamy and defense of all‐purpose territories are core characteristics of both species, mate choice has long‐term consequences. Therefore, red wolves may choose similar‐sized mates to acquire partners that behave similarly to themselves in the use of space and diet. We observed multiple factors influencing breeding pair formation by red wolves and found that most wolves paired with similar‐sized conspecifics and wolves that formed congeneric pairs with nonwolves (coyotes and hybrids) were mostly female wolves, the smaller of the two sexes. Additionally, we observed that lower red wolf abundance relative to nonwolves and the absence of helpers increased the probability that wolves consorted with nonwolves. However, successful pairings between red wolves and nonwolves were associated with wolves that maintained small home ranges. Behaviors associated with territoriality are energetically demanding and behaviors (e.g., aggressive interactions, foraging, and space use) involved in maintaining territories are influenced by body size. Consequently, we propose the hypothesis that size disparities between consorting red wolves and coyotes influence positive assortative mating and may represent a reproductive barrier between the two species. We offer that it may be possible to maintain wild populations of red wolves in the presence of coyotes if management strategies increase red wolf abundance on the landscape by mitigating key threats, such as human‐caused mortality and hybridization with coyotes. Increasing red wolf abundance would likely restore selection pressures that increase mean body and home‐range sizes of red wolves and decrease hybridization rates via reduced occurrence of congeneric pairs.     

Molecular systematics of Mesocestoides sPP (cestoda: mesocestoididae) from domestic dogs (Canis familiaris) and coyotes (Canis latrans)

The genus Mesocestoides Vaillant, 1863 includes tapeworms of uncertain phylogenetic affinities and with poorly defined life histories. We previously documented 11 cases of peritoneal cestodiasis in dogs (Canis familiaris L.) in western North America caused by metacestodes of Mesocestoides spp. In the current study, DNA sequences were obtained from metacestodes collected from these dogs (n = 10), as well as proglottids from dogs (n = 3) and coyotes (Canis latrans Say, 1823 [n = 2]), and tetrathyridia representing laboratory isolates of M. corti (n = 3), and these data were analyzed phylogenetically. Two nuclear genetic markers, 18S ribosomal DNA and the second internal-transcribed spacer (ITS 2), were sequenced. Phylogenetic analysis of the 18S rDNA data recovered a monophyletic group composed of all samples of Mesocestoides spp., distinct from closely related outgroup taxa (Amurotaenia Akhmerov, 1941 and Tetrabothrius Rudolphi, 1819). Initial analysis of the ITS 2 data resolved 3 clades within Mesocestoides. Two proglottids from dogs formed a basal clade, a second clade was represented by tetrathyridial isolates, and a third clade included all other samples. Interpretation of these data from an apomorphy-based perspective identified 6 evolutionary lineages. We also assessed whether metacestodes from dogs (n = 4) are capable of asexual proliferation in laboratory mice. One tetrathyridial and 2 acephalic isolates from dogs proliferated asexually. Further investigation is warranted to determine which of the lineages represent distinct species and to determine the life history strategies of Mesocestoides spp.