Genetic structure of Himalayan marmot (Marmota himalayana) population alongside the Qinghai–Tibet Railway

In order to verify the effect of social behavior and geographical isolation on the genetic structure of the Himalayan marmot (Marmota himalayana) population, we examined the genetic diversity of Himalayan marmots alongside the Qinghai–Tibet Railway using microsatellite markers. Eight microsatellite loci were used to examine 120 animals of 4 populations: Ulan (U), Delhi (D), Tuotuohe (T) and Ando (A). The results show that: (1) Himalayan marmots alongside the Qinghai–Tibet Railway are highly genetically diversified. The allele number (Na), effective allele number (Ne), observed heterozygosity (Ho), Nei’s expected heterozygosity (He) and polymorphism information content (PIC) of the total Himalayan marmot population were 4.75, 3.0332, 0.6990, 0.6672, 0.6102, respectively. (2) Himalayan marmots may be able to avoid inbreeding by a mechanism that will prevent the genetic diversity reduction caused by their social lifestyle. Heterozygote excess was observed at most loci. The inbreeding coefficients within the subpopulation (F_IS), in the total population (F_IT), the differentiation index of population (F_ST), and the gene flow (Nm) were ?0.2265, ?0.0477, 0.1458, and 1.4646, respectively. (3) The genetic differentiation of the Himalayan marmot population was in accordance with Wright’s “isolation by distance” theory. The Mantel test indicates that the correlation between genetic distance and geographic distance was significant (P < 0.05, r = 0.698). (4) Each of the four geographical populations had moderate differentiation. Both geographic distance and isolation could affect the population genetic structure of the Himalayan marmot. The maximum gene flow (3.5915), the smallest genetic differentiation index (0.0651), the lowest genetic distance (0.0700) and the highest genetic identity (0.9526) were all between the Ulan population and Delhi populations. (5) The cluster analysis, based on Nei’s standard genetic distance, showed that the populations of Delhi and Ulan were first merged in a cluster, and then Tuotuohe population was merged in the clustering. The Ando population was the last element in the clustering.     

喜马拉雅旱獭制动性麻醉方法

目的将盐酸氯胺酮用于喜马拉雅旱獭的麻醉,探讨不同剂量麻醉效果,为合理使用提供参考。方法将30只喜马拉雅旱獭随机分为3组,按15、45、90mg/kg体重给予盐酸氯胺酮,行后肢肌肉注射麻醉,观察临床表现和诱导时间及麻醉时间。结果给予盐酸氯胺酮后喜马拉雅旱獭分别在402.0±60.7s、372.0±72.0s、222.0±66.0s进入麻醉状态,维持时间分别为558.0±96.0s、1344.0±264.0s、3366.0±696.0s。随剂量的增加,麻醉时间相应增加。结论盐酸氯胺酮对喜马拉雅旱獭进行肌肉注射麻醉是有效和安全的,在应用中还可以根据实验需要选择3种剂量进行麻醉,为喜马拉雅旱獭得到广泛应用奠定了基础。     

蒙古旱獭体重体长变化及其年龄划分的研究

本文报告了645只蒙古旱獭体重体长变化与年龄的关系。结果表明:体重体长随年龄增长而递增,但体重和体长的增长速度和幅度不同。体重增长速度较快,幅度较大;体长增长速度较慢,幅度较小。经相关分析证明:体重体长与年龄呈正相关,相关系数和回归方程为: Y_w=1377.16x~(O.7729),R_w=0.9970; Y_L=33.95x~(0.2529),R_L=0.9947。 并根据相邻两个年龄组间体重均数有显著性差异(P<0.01),频数分布重叠不明显;组内变异具有一致性等特征,参考各年龄组蒙古早獭体重标准值(Mean ±Sx),划分了各年龄组早獭的体重范围。     

Genetic structure of Himalayan marmot (Marmota himalayana) population alongside the Qinghai–Tibet Railway

In order to verify the effect of social behavior and geographical isolation on the genetic structure of the Himalayan marmot (Marmota himalayana) population, we examined the genetic diversity of Himalayan marmots alongside the Qinghai–Tibet Railway using microsatellite markers. Eight microsatellite loci were used to examine 120 animals of 4 populations: Ulan (U), Delhi (D), Tuotuohe (T) and Ando (A). The results show that: (1) Himalayan marmots alongside the Qinghai–Tibet Railway are highly genetically diversified. The allele number (Na), effective allele number (Ne), observed heterozygosity (Ho), Nei’s expected heterozygosity (He) and polymorphism information content (PIC) of the total Himalayan marmot population were 4.75, 3.0332, 0.6990, 0.6672, 0.6102, respectively. (2) Himalayan marmots may be able to avoid inbreeding by a mechanism that will prevent the genetic diversity reduction caused by their social lifestyle. Heterozygote excess was observed at most loci. The inbreeding coefficients within the subpopulation (F_IS), in the total population (F_IT), the differentiation index of population (F_ST), and the gene flow (Nm) were ?0.2265, ?0.0477, 0.1458, and 1.4646, respectively. (3) The genetic differentiation of the Himalayan marmot population was in accordance with Wright’s “isolation by distance” theory. The Mantel test indicates that the correlation between genetic distance and geographic distance was significant (P < 0.05, r = 0.698). (4) Each of the four geographical populations had moderate differentiation. Both geographic distance and isolation could affect the population genetic structure of the Himalayan marmot. The maximum gene flow (3.5915), the smallest genetic differentiation index (0.0651), the lowest genetic distance (0.0700) and the highest genetic identity (0.9526) were all between the Ulan population and Delhi populations. (5) The cluster analysis, based on Nei’s standard genetic distance, showed that the populations of Delhi and Ulan were first merged in a cluster, and then Tuotuohe population was merged in the clustering. The Ando population was the last element in the clustering.     

人工饲养条件下喜玛拉雅旱獭寄生虫病综合防治

目的制订规模化饲养喜玛拉雅旱獭寄生虫病综合防治措施,提高喜马拉雅旱獭的数量和质量及保证动物实验结果的准确性.方法 根据喜玛拉雅旱獭寄生虫检测结果,选择1%伊维菌素注射液按每千克体重0.02 ml皮下注射,连用5～7 d,制定并落实标本兼治的防疫措施和日常卫生消毒管理制度.结果给药后10 d和30 d取新鲜粪便检测,体内外寄生虫0%感染,停药90 d后未检测到寄生虫成虫和虫卵.结论通过采取药物驱虫和日常卫生管理及综合防治措施,使喜马拉雅旱獭寄生虫病控制收到良好效果.     

Ranking Mahalanobis Distance Models for Predictions of Occupancy From Presence-Only Data

ABSTRACT The Mahalanobis distance statistic (D²) has emerged as an effective tool to identify suitable habitat from presence data alone, but there has been no mechanism to select among potential habitat covariates. We propose that the best combination of explanatory variables for a D² model can be identified by ranking potential models based on the proportion of the entire study area that is classified as potentially suitable habitat given that a predetermined proportion of occupied locations are correctly classified. In effect, our approach seeks to minimize errors of commission, or maximize specificity, while holding the omission error rate constant. We used this approach to identify potentially suitable habitat for the Olympic marmot (Marmota olympus), a declining species endemic to Olympic National Park, Washington, USA. We compared models built with all combinations of 11 habitat variables. A 7-variable model identified 21,143 ha within the park as potentially suitable for marmots, correctly classifying 80% of occupied locations. Additional refinements to the 7-variable model (e.g., eliminating small patches) further reduced the predicted area to 18,579 ha with little reduction in predictive power. Although we sought a model that would allow field workers to find 80% of Olympic marmot locations, in fact, <3% of 376 occupied locations and <9% of abandoned locations were >100 m from habitat predicted by the final model, suggesting that >90% of occupied marmot habitat could be found by observant workers surveying predicted habitat. The model comparison procedure allowed us to identify the suite of covariates that maximized specificity of our model and, thus, limited the amount of less favorable habitat included in the final prediction area. We expect that by maximizing specificity of models built from presence-only data, our model comparison procedure will be useful to conservation practitioners planning reintroductions, searching for rare species, or identifying habitat for protection.     

喜马拉雅旱獭的洞穴特征及其生态意义

穴居性动物的洞穴对其生存有着重要的影响。为了解喜马拉雅旱獭（Marmota himalayana）利用洞穴特征及其生态意义,于2017年5月至10月以及2018年4月至5月在四川省阿坝州若尔盖县班佑乡多玛村对30对喜马拉雅旱獭繁殖对所利用的洞穴进行了定量研究。按照当年被频繁利用的洞穴（夜宿洞与繁殖洞）与临时利用的洞穴1∶2的比例取样,共测量了90个洞穴的7个物理特征参数,比较了不同类型洞穴的物理特征差异。结果表明：（1）当地喜马拉雅旱獭利用洞穴外径的长轴和短轴分别为59.3 ± 21.9 (16~100) 和45.8 ± 20.5 (18~100) cm,内径内横径和内竖径分别为24.4 ± 4.0 (16~39) 和19.7 ± 3.5 (15~39) cm;（2）洞道首段长为127.3 ± 43.3 (60~240) cm;（3）洞道首段倾斜角度为45.7° ± 9.5° (20°~72°);（4）洞口朝向角度为195.8° ± 96.2° (3°~356°)。除了夜宿洞与繁殖洞临时洞的内竖径有显著性差异,其它不同洞穴类型之间的物理特征基本一致。喜马拉雅旱獭利用洞穴物理特征参数表明其洞穴具有躲避天敌、抵御不良天气、良好的排水性能以及维持洞穴小气候稳定的功能。大部分洞穴之间的物理特征基本一致结合行为观察,说明喜马拉雅旱獭存在年际间的换洞行为。     

喜马拉雅旱獭线粒体DNA控制区遗传多样性及系统发育

喜马拉雅旱獭是青藏高原的优势种,数量多、分布广,全面了解其遗传背景对该地区旱獭资源的保护与合理利用具有重要的意义。本研究以青藏高原云南、西藏和青海三省区共13个地理种群计258只旱獭为研究对象,PCR扩增获得线粒体DNA控制区基因部分序列(887 bp),并运用种群遗传学方法进行遗传多样性分析。结果显示:258份样品共发现了84个变异位点(9.40%),定义了68种单倍型,其单倍型多样性(h)平均值为0.968±0.003、核苷酸多样性(π)平均值为0.017 25±0.016 37,种群总体遗传多样性较高。AMOVA方差分析显示13个地理种群间存在着明显的遗传分化(Fst=0.620 67,P<0.001),种群间基因交流多数较低(Nm<1)。基于单倍型构建的系统发育树中13个地理种群的喜马拉雅旱獭聚为两支,其中来自青藏高原西南地区(西藏安多、青海格尔木、青海囊谦、云南迪庆)的18个单倍型聚成一个大的分支(A支),其余50个单倍型聚为一个大的分支(B支),在NETWORK网络图中也可见到相似网络拓扑结构。研究结果显示青藏高原喜马拉雅旱獭种群以唐古拉山脉为界分为两个大的种群,说明地理隔离是影响喜马拉雅旱獭种群动态变化的主要因素。     

Intranuclear rodlets in woodchuck thyroid follicular cells

Summary Intranuclear rodlets are seen in thyroid follicular cells of woodchucks fixed during summer and fall. They are not observed in winter and spring animals. A functional significance of these structures is suggested.Supported in part by PHS 05429-13-5 (P.P. Krupp, Department of Anatomy) and PHS R01 10254 (E.A. Sims, Metabolic Unit, Department of Medicine)