单胺氧化酶B单核苷酸基因多态性与犬旷场行为关联分析

采用旷场行为测试方法, 测定204条德国牧羊犬、拉布拉多犬、史宾格犬二月龄幼犬在新异环境下的兴奋性和探索活动, 同时应用RFLP-PCR方法检测单胺氧化酶B(Monoamine Oxidase B, MAOB)基因的多态性, 分析MAOB基因的基因型和基因频率在品种间的分布差异以及基因多态性与旷场测验中行为参数的相互关系, 发现MAOB基因型频率与基因频率在犬品种之间差异极显著(P<0.01), MAOB基因型与幼犬在旷场中的走动时间、趴卧时间、跨格次数、站立扒墙次数有关(P<0.01或P<0.05), 对运动姿势改变次数也有一定影响(P=0.064)。其中, TT基因型犬的走动时间和跨格次数均高于TC型和CC型犬(P<0.05), 运动姿势改变次数和站立扒墙次数高于CC型犬(P<0.05); 而CC型个体的趴卧时间高于TT型个体(P<0.05)。MAOB基因对走动时间和跨格次数的加性遗传效应达极显著(P<0.01), 对运动姿势改变次数、站立扒墙次数和趴卧时间有显著的加性效应(P<0.05)。实验结果表明, MAOB基因与幼犬在旷场测验中的运动、兴奋性和探索活动有关, TT基因型对运动、兴奋性和探索活动具有正遗传效应。     

单胺氧化酶B基因单核苷酸多态性与藏獒对陌生人攻击行为的关联分析

采用行为测试的方法,测定藏獒和拉布拉多犬在陌生人接近时的攻击行为差异,应用PCR-RFLP技术检测单胺氧化酶B(MAOB)基因第3外显子单核苷酸多态性,分析其在藏獒(陌生人接近时进行攻击)和拉布拉多犬(陌生人接近时无攻击行为)两个品种间基因型频率与基因频率分布差异.结果 表明:MAOB基因型频率与基因频率在两个品种中分布差异不显著(P＞0.05).x2适合性检验显示,藏獒处于Hardy-Weinberg极不平衡状态(P＜0.01),拉布拉多犬处于Hardy-Weinberg平衡状态(P＞0.05).藏獒和拉布拉多犬品种间,在陌生人接近时的攻击行为差异与MAOB基因T119C多态性可能无直接关系.     

活跃性和社会性对中华倒刺鲃集群行为的影响

为考察群体中不同的个性组成对鱼类集群行为的影响及其内在机制,选取中华倒刺鲃(Spinibarbus sinensis)幼鱼为实验对象,依次测定其活跃性和社会性,随后分别根据活跃性和社会性的高低分为高、低和混合活跃性(或社会性)鱼群,考察鱼群中不同个性组成对集群时的整体运动特征以及每尾鱼的个体运动特征的影响。研究发现：(1)中华倒刺鲃的个性特征稳定且个体间变异较大;(2)高活跃性鱼群的运动时间比和速度同步性均大于低活跃性鱼群,而混合鱼群位于二者之间且与两个同质性鱼群均无显著差异;高社会性鱼群速度同步性显著小于低社会性和混合社会性鱼群,而后两者之间没有显著差异。(3)活跃性特征与集群运动时每尾鱼的运动特征(速度及其同步性等)相关,社会性特征不仅与上述运动特征关联,还与凝聚力大小(距鱼群质心距离)相关。研究表明：(1)鱼群的活跃性和社会性组成均对集群行为产生重要影响,但其内在机制截然不同。主要表现为：就活跃性而言,群体的运动状态是由群体中所有成员共同决定(平均决定机制);就社会性而言,少数低社会性成员对鱼群的运动水平表现有着主导作用(少数决定机制);(2)实验鱼的活跃性在集群行为中得到了较大...     

鸡Myostatin基因单核苷酸多态性及其对屠体性状的遗传效应分析

以180只3个品系的温岭草鸡为材料, 采用PCR-RFLP方法对鸡MSTN基因外显子1的2个多态位点进行研究, 并分析对屠体性状的遗传效应。Bsh1236Ⅰ识别G(2100)A突变, 产生MN和NN 2种基因型, MspⅠ识别G(2109)A突变, 产生AA、AB和BB 3种基因型, 联合2个位点分析出现了5种基因型。基因型频率在品系间的c2检验表明差异均不显著(P＞0.05)。方差分析显示不同基因型的屠宰率有显著或极显著的差异(P＜0.01或P＜0.05)。多重比较显示：杂合型MN的腹脂重和屠宰率显著(P＜0.05)高于突变型NN; 杂合型AB的胸肌重和胸肌率显著(P＜0.01或P＜0.05 )高于基因型AA, 基因型AA的腹脂重和腹脂率都极显著(P＜0.01)高于突变型BB, 在腿肌重性状上, BB型显著(P＜0.05)低于AA型和AB型;2个位点联合分析时, NA/MA基因型的腹脂重、腹脂率和胸肌率均极显著(P＜0.01)高于或低于其他基因型。     

产前应激子代大鼠海马核转录因子-кB表达的性别差异

;本研究采用免疫组织化学和Western blot检测NF-кB p65/p50在产前应激子代海马的表达,并探讨其表达是否存在性别差异.研究结果显示,在雌性子代,中、晚期应激组海马齿状回p65表达显著低于对照组(P＜0.01),而海马各区p50表达均显著高于对照组(P＜0.01),中、晚期应激组间p65和p50表达均有显著差异(P＜0.01).在雄性子代,中、晚期应激组海马齿状回p65表达显著高于对照组(P＜0.01),晚期应激组海马各区p50表达均显著低于对照组(P＜0.05,P＜0.01),中、晚期应激组间p65和p50表达均有显著差异(P＜0.01).雌、雄子代比较,对照组雌、雄p65表达差异极显著(P＜0.01),p50仅在海马CA1区表达差异极显著(P＜0.01);中期应激组雌、雄子代大鼠海马p65/p50表达无显著差异;晚期应激组雌、雄海马p65/p50表达均有极显著差异(P＜0.01).Western blot与免疫组织化学结果基本一致.结果表明,产前不同时期的应激显著影响子代海马NF-кB p65和p50表达,且有性别差异,这可能是产前应激对子代雌、雄大鼠学习记忆能力影响差异的机制之一.     

两种生态相关猎物鱼个性的种间差异及其捕食者效应

为探究不同猎物鱼个性的种间差异及其捕食者效应, 实验以乌鳢(Channa argus)为天然的捕食者, 选取自然界通常形成混合种群的高体鳑鲏(Rhodeus ocellatus)和麦穗鱼(Pseudorasbora parva)作为猎物鱼, 设置有捕食者和无捕食者处理组开展同质园实验; 之后, 分别测定了经历捕食环境处理的两种猎物鱼的探索性、活跃性和勇敢性3类个性特征, 分析两种猎物鱼个性特征的种间差异及其环境依赖性。结果发现: (1)高体鳑鲏和麦穗鱼个性存在显著的种间差异, 不管是否经历捕食者处理, 高体鳑鲏的探索性、活跃性和勇敢性均显著强于麦穗鱼(P<0.05); (2)捕食者处理导致高体鳑鲏和麦穗鱼探索性和勇敢性有增强的趋势, 但对二者的活跃性均无显著影响(P>0.05); (3)捕食者处理弱化了高体鳑鲏和麦穗鱼不同个性特征的种间差异, 强化了各自不同个性特征的偶联。结果提示: 两种猎物鱼个性特征的种间差异显著且均具有捕食者效应, 有捕食者环境下两种猎物鱼个性特征的种间差异变小, 表现出趋同化适应的趋势。     

圈养林麝(Moschus berezovskii)个性及与麝香分泌和繁殖成效的关系

于2016年6月20日至8月10日在四川马尔康林麝繁育场开展,采用基于量表的个性评价法对172头（雌麝59头,雄麝113头）圈养林麝进行了个性评价,建立了圈养林麝个性维度,并探索了个性维度与其麝香分泌和繁殖成效的关系。结果表明：因子分析各项载荷值均大于0.4,Cronbach''s α分析结果为0.648,表明个性量表具有较好的一致性信度和结构效度。此外,特征根大于1时,圈养林麝的侵略性、活跃性、刻板性、胆怯性及社会性五大个性维度可解释70.77%的个性信息,并通过聚类分析,进一步验证了维度划分的合理性;雄性林麝的社会性维度和麝香分泌量存在显著正相关（r=0.234,P < 0.05）,社会性越强（展现出更多的互饰接触、共同摄食等亲和行为的个体）,其泌香量越高;侵略性（r=0.463,P < 0.05）、活跃性（r=0.440,P < 0.05）、刻板性（r=0.595,P < 0.05）与雌性分娩时间存在显著正相关关系,即个性越强,分娩时间越晚,此外,刻板性与产仔数呈显著负相关（r=-0.341,P < 0.05）,表明圈养林麝的繁殖成效主要受刻板性维度影响,刻板性强的个体对繁殖成效会有一个负面的效应。     

医学生气质性乐观与抑郁生活满意度的关系

目的 探讨医学本科生气质性乐观与抑郁体验、生活满意度的关系,为改善医学生的心理健康提供依据.方法 方便抽取某医学院校在校本科生300名,采用生活取向测量问卷(LOT)、抑郁体验问卷(DEQ)、生活满意度问卷(SWLS)进行调查.结果 男女医学生乐观水平差异无统计学意义(P＞0.05),独生子女乐观水平显著高于非独生子女,差异有统计学意义(P＜0.01);乐观维度和生活满意度显著正相关(r=0.40,P＜0.01),悲观维度与无助性抑郁和内射性抑郁维度显著正相关(r=0.39,0.49,P＜0.01);悲观因子显著正向预测抑郁(β=0.491,P＜0.01),乐观因子显著正向预测生活满意度(β=0.357,P＜0.01).结论 医学生的气质性乐观和抑郁、生活满意度有着密切关系,气质性乐观可能是影响医学生心理健康的重要因素.     

老年轻度认知障碍患者生活高危因素探讨

目的:探讨生活高危因素对老年轻度认知障碍的影响。方法:应用简明精神状态量表(MMSE)、蒙特利尔认知测验量表(MoCA)、临床痴呆评定量表(CDR)和生活高危因素量表对219例老年人进行调查,分析生活高危因素对老年轻度认知障碍的影响。结果:女性患MCI风险高于男性(P=0.03);文盲组患MCI风险高于小学组,小学组高于初中及以上组(P=0.00);农民组患MCI风险高于工人组,工人组高于管理人员组(P=0.01);农村居民患MCI风险高于城市居民(P=0.01);运动影响MCI发病,不运动组患MCI风险高于运动组(P=0.00),运动频率<4次/周高于运动频率≥4次/周(P=0.00),运动年数≤10年组高于运动>10年组(P=0.01);业余爱好影响MCI发病,无业余爱好组患MCI风险高于有业余爱好组(P=0.00),业余爱好史≤10年组高于业余爱好史>10组(P=0.00)。不同年龄的老年人其MCI发病风险无统计学差异(P>0.05);吸烟、饮酒、喝茶等不同年数及频率的老年人其MCI发病风险无统计学差异(P>0.05);是否午休及不同午休频率和不同每晚睡眠时间的老年人其MCI发病风险无统计学差异(P>0.05)。结论:性别、教育程度、职业、居住地、运动时间及频率、业余爱好时间等因素与老年MCI发病有关。     

盐度、温度对卵形鲳鲹选育群体肝抗氧化酶活力的影响

通过盐度渐变和温度骤变的方法,分别研究了不同盐度(10、20、30、40)处理和不同温度(18.0℃、21.0℃、24.6℃、29.0℃、32.0℃)处理对卵形鲳鲹(Trachinotus ovatus)选育群体肝超氧化物歧化酶(SOD)、过氧化氢酶(CAT)和谷胱甘肽过氧化物酶(GPX)活力的影响.在实验结束时,盐度10组酶活力与对照组无显著差异(P＞0.05),盐度20组SOD活力极显著低于对照组(P＜0.01);盐度40组120 h时,SOD和GPX活力极显著低于对照组(P＜0.01),CAT活力与对照组差异不显著(P＞0.05).18.0℃和21.0℃ SOD活力在1、3、6、12、24 h这5个取样时间点均高于对照组,CAT活力在实验结束时(24 h)极显著高于对照组(P ＜0.01);29.0℃SOD和CAT活力在实验结束时(24 h)显著高于对照组(P＜0.05);32.0℃ SOD和CAT活力在5个取样时间点均显著低于对照组(P＜0.05).结果表明,适当的盐度或温度变化可以改变卵形鲳鲹肝抗氧化酶活力,达到机体耐受极限时酶活力下降.     

Characterisation of the main drivers of intra- and inter- breed variability in the plasma metabolome of dogs

Introduction

Dog breeds are a consequence of artificial selection for specific attributes. These closed genetic populations have metabolic and physiological characteristics that may be revealed by metabolomic analysis.

Objectives

To identify and characterise the drivers of metabolic differences in the fasted plasma metabolome and then determine metabolites differentiating breeds.

Methods

Fasted plasma samples were collected from dogs maintained under two environmental conditions (controlled and client-owned at home). The former (n = 33) consisted of three breeds (Labrador Retriever, Cocker Spaniel and Miniature Schnauzer) fed a single diet batch, the latter (n = 96), client-owned dogs consisted of 9 breeds (Beagle, Chihuahua, Cocker Spaniel, Dachshund, Golden Retriever, Greyhound, German Shepherd, Labrador Retriever and Maltese) consuming various diets under differing feeding regimens. Triplicate samples were taken from Beagle (n = 10) and Labrador Retriever (n = 9) over 3 months. Non-targeted metabolite fingerprinting was performed using flow infusion electrospray-ionization mass spectrometry which was coupled with multivariate data analysis. Metadata factors including age, gender, sexual status, weight, diet and breed were investigated.

Results

Breed differences were identified in the plasma metabolome of dogs housed in a controlled environment. Triplicate samples from two breeds identified intra-individual variability, yet breed separation was still observed. The main drivers of variance in dogs maintained in the home environment were associated with breed and gender. Furthermore, metabolite signals were identified that discriminated between Labrador Retriever and Cocker Spaniels in both environments.

Conclusion

Metabolite fingerprinting of plasma samples can be used to investigate breed differences in client-owned dogs, despite added variance of diet, sexual status and environment.

     

Element Status in Different Breeds of Dogs

The serum levels of copper, zinc, iron, manganese, nickel, cadmium, cobalt, sodium, potassium, calcium, and magnesium were determined in seven different breeds of dogs: Pointer, Poodle, Setter, Labrador Retriever, Golden Retriever, German Shepherd, and Mallinois. Only slight variations were found among the different breeds, and the results presented in this study can be used for laboratory studies in veterinary science.     

Breed-typical behaviour in dogs—Historical remnants or recent constructs?

Dogs show considerable variation in morphology, genetics and behaviour caused by long periods of artificial selection. This is evident in the large number of breeds we have today. Behavioural differences among breeds have often been regarded as remnants from past selection during the breeds’ origin. However, the selection in many breeds has, during the last decades, gone through great changes, which could have influenced breed-typical behaviour. In order to investigate this, breed differences were studied using data from a standardized behavioural test from 13,097 dogs of 31 breeds from the Swedish dog population. Based on the test results, breed scores were calculated for four behavioural traits: playfulness, curiosity/fearlessness, sociability and aggressiveness. These traits have previously been found to be stable and valid, and hence regarded as personality traits in the dog. The present results suggested large differences between breeds in all of the investigated traits, even though there were within-breed variations. No relationships between breed-characteristic behaviour and function in the breeds’ origins were found. Instead, there were correlations between breed scores and current use of the breeding stocks, which suggest that selection in the recent past has affected breed-typical behaviour. The breeds’ use in dog shows, the dominating use in general, was negatively correlated with all investigated traits, both in sires and in dams. In contrast, use in Working dog trials was positively correlated with playfulness and aggressiveness in sires. Thus, these results suggest that selection for dog show use is positively correlated with social and non-social fearfulness, and negatively with playfulness, curiosity in potentially threatening situations and aggressiveness, whereas selection for Working dog use is positively correlated with playfulness and aggressiveness. Furthermore, correlation analyses show that popular breeds have higher sociability and playfulness scores than less popular breeds, suggesting that a positive attitude towards strangers is an important characteristic of a functional pet dog and desirable by dog owners. This indicates that selection towards use in dog shows may be in conflict with pet dog selection. Furthermore, these results suggest that basic dimensions of dog behaviour can be changed when selection pressure changes, and that the domestication of the dog still is in progress. A standardized behavioural test, like the one used in this study, is suggested to be highly useful as a tool in dog breeding programs.     

Characterization of human-dog social interaction using owner report

Dog owners were surveyed for observations of social behaviors in their dogs, using questions adapted from the human Autism Diagnostic Observation Schedule (ADOS) pre-verbal module. Using 939 responses for purebred and mixed-breed dogs, three factors were identified: initiation of reciprocal social behaviors (INIT), response to social interactions (RSPNS), and communication (COMM). There were small or no effects of sex, age, breed group or training. For six breeds with more than 35 responses (Border Collie, Rough Collie, German Shepherd, Golden Retriever, Labrador Retriever, Standard Poodle), the behaviors eye contact with humans, enjoyment in interactions with human interaction, and name recognition demonstrated little variability across breeds, while asking for objects, giving/showing objects to humans, and attempts to direct humans’ attention showed higher variability across these breeds. Breeds with genetically similar backgrounds had similar response distributions for owner reports of dog response to pointing. When considering these breeds according to the broad categories of “herders” and “retrievers,” owners reported that the “herders” used more eye contact and vocalization, while the “retrievers” used more body contact. Information regarding social cognitive abilities in dogs provided by owner report suggest that there is variability across many social cognitive abilities in dogs and offers direction for further experimental investigations.     

Evaluation of RDS/Peripherin and ROM1 as candidate genes in generalised progressive retinal atrophy and exclusion of digenic inheritance

Generalised progressive retinal atrophy (gPRA) is a heterogeneous group of hereditary diseases causing degeneration of the retina in dogs and cats. As a combination of mutations in the RDS/Peripherin and the ROM1 genes leads to the phenotype of retinitis pigmentosa in man we first performed mutation analysis to screen these genes for disease causing mutations followed by the investigation of a digenic inheritance in dogs. We cloned the RDS/Peripherin gene and investigated the RDS/Peripherin and ROM1 genes for disease causing mutations in 13 gPRA-affected dog breeds including healthy animals, obligate gPRA carriers and gPRA-affected dogs. We screened for mutations using single strand conformation polymorphism (SSCP) analysis. Sequence analysis revealed several sequence variations. In the coding region of the RDS/Peripherin gene three nucleotide exchanges were identified (A277C; C316T; G1255A), one of which leads to an amino acid substitution (Ala339Thr). Various silent sequence variations were found in the coding region of the ROM1 gene (A536G, G1006A, T1018C, T1111C, C1150T, C1195T), as well as an amino acid substitution (G252T; Ala54Ser). By excluding the respective gene as a cause for gPRA several sequence variations in the intronic regions were investigated. None of these sequence variations cosegregated with autosomal recessively (ar) transmitted gPRA in 11 breeds. The candidate gene RDS/Peripherin obviously does not harbour the critical mutation causing the autosomal recessive form of gPRA because diseased individuals show heterozygous genotypes for sequence variations in the Miniature Poodle, Dachshund, Australian Cattle Dog, Cocker Spaniel, Chesapeake Bay Retriever, Entlebucher Sennenhund, Sloughi, Yorkshire Terrier, Tibet Mastiff, Tibet Terrier and Labrador Retriever breeds. In the following breeds the ROM1 gene was also excluded indirectly for gPRA: Miniature Poodle, Dachshund, Australian Cattle Dog, Sloughi, Collie, Tibet Terrier, Labrador Retriever and Saarloos/Wolfhound. Digenic inheritance for gPRA is practically excluded for both these genes in four breeds: Miniature Poodle, Dachshund, Labrador Retriever and Saarloos/Wolfhound.     

Genome-wide association analysis of canine atopic dermatitis and identification of disease related SNPs

In humans, genome-wide association studies (GWAS) have been shown to be an effective and thorough approach for identifying polymorphisms associated with disease phenotypes. Here, we describe the first study to perform a genome-wide association study in canine atopic dermatitis (cAD) using the Illumina Canine SNP20 array, containing 22,362 single-nucleotide polymorphisms (SNPs). The aim of the study was to identify SNPs associated with cAD using affected and unaffected Golden Retrievers. Further validation studies were performed for potentially associated SNPs using Sequenom genotyping of larger numbers of cases and controls across eight breeds (Boxer, German Shepherd Dog, Labrador, Golden Retriever, Shiba Inu, Shih Tzu, Pit Bull, and West Highland White Terriers). Using meta-analysis, two SNPs were associated with cAD in all breeds tested. RS22114085 was identified as a susceptibility locus (p?=?0.00014, odds ratio?=?2) and RS23472497 as a protective locus (p?=?0.0015, odds ratio?=?0.6). Both of these SNPs were located in intergenic regions, and their effects have been demonstrated to be independent of each other, highlighting that further fine mapping and resequencing is required of these areas. Further, 12 SNPs were validated by Sequenom genotyping as associated with cAD, but these were not associated with all breeds. This study suggests that GWAS will be a useful approach for identifying genetic risk factors for cAD. Given the clinical heterogeneity within this condition and the likelihood that the relative genetic effect sizes are small, greater sample sizes and further studies will be required.     

Exclusion of the PDE6A gene for generalised progressive retinal atrophy in 11 breeds of dog

The cyclic guanosine monophosphate specific phosphodiesterase (cGMP-specific PDE) is a key enzyme in the phototransduction cascade of the vertebrate retina. This enzyme consists of two catalytic alpha and beta subunits, two identical inhibitory gamma subunits as well as a delta subunit. Mutations in PDE6A and the PDE6B genes lead to autosomal recessive (ar) forms of retinitis pigmentosa (RP) in human and to the homologous disease in dogs, designated generalised progressive retinal atrophy (gPRA). We investigated the PDE6A gene in 13 gPRA-affected dog breeds including healthy animals, obligate gPRA carriers and gPRA-affected dogs. In the coding region of PDE6A only a rare sequence variation (G103A; Asp35Asn) was found in exon 1 of two healthy Tibet Terriers and one affected Cocker Spaniel. Using single-stranded conformation polymorphism (SSCP) analyses we detected several sequence variations in eight of the PDE6A introns in different investigated breeds. Most informative for excluding the PDE6A gene as a cause for gPRA was a polymorphic microsatellite ((GT)10CG(GT)2CG(GT)12) in intron 14 and four sequence variations in intron 18 for almost all breeds investigated. The sequence variations of PDE6A did not segregate together with gPRA in 11 breeds. Since diseased animals were heterozygous for the polymorphisms, the PDE6A gene is unlikely to harbour the critical mutation causing gPRA in the following breeds: Chesapeake Bay Retriever. Entlebucher Sennenhund, Labrador Retriever. Tibet Mastiff, Dachshund (long- and wire-haired), Tibetan Terrier, Miniature Poodle. Australian Cattle Dog, Cocker Spaniel, Saarloos/Wolfshound, Sloughi.     

Ultra high performance liquid chromatography–high resolution mass spectrometry plasma lipidomics can distinguish between canine breeds despite uncontrolled environmental variability and non-standardized diets

Introduction and objectives

The purpose of this study was to use high accurate mass metabolomic profiling to investigate differences within a phenotypically diverse canine population, with breed-related morphological, physiological and behavioural differences. Previously, using a broad metabolite fingerprinting approach, lipids appear to dominate inter- and intra- breed discrimination. The purpose here was to use Ultra High Performance Liquid Chromatography–High Resolution Mass Spectrometry (UHPLC–HRMS) to identify in more detail, inter-breed signatures in plasma lipidomic profiles of home-based, client-owned dogs maintained on different diets and fed according to their owners’ feeding regimens.

Methods

Nine dog breeds were recruited in this study (Beagle, Chihuahua, Cocker Spaniel, Dachshund, Golden Retriever, Greyhound, German Shepherd, Labrador Retriever and Maltese: 7–12 dogs per breed). Metabolite profiling on a MTBE lipid extract of fasted plasma was performed using UHPLC-HRMS.

Results

Multivariate modelling and classification indicated that the main source of lipidome variance was between the three breeds Chihuahua, Dachshund and Greyhound and the other six breeds, however some intra-breed variance was evident in Labrador Retrievers. Metabolites associated with dietary intake impacted on breed-associated variance and following filtering of these signals out of the data-set unique inter-breed lipidome differences for Chihuahua, Golden Retriever and Greyhound were identified.

Conclusion

By using a phenotypically diverse home-based canine population, we were able to show that high accurate mass lipidomics can enable identification of metabolites in the first pass plasma profile, capturing distinct metabolomic variability associated with genetic differences, despite environmental and dietary variability.

     

Differential genetic regulation of canine hip dysplasia and osteoarthritis

Background

Canine hip dysplasia (HD) is a common polygenic trait characterized by hip malformation that results in osteoarthritis (OA). The condition in dogs is very similar to developmental dysplasia of the human hip which also leads to OA.

Methodology/Principal Findings

A total of 721 dogs, including both an association and linkage population, were genotyped. The association population included 8 pure breeds (Labrador retriever, Greyhounds, German Shepherd, Newfoundland, Golden retriever, Rottweiler, Border Collie and Bernese Mountain Dog). The linkage population included Labrador retrievers, Greyhounds, and their crosses. Of these, 366 dogs were genotyped at ∼22,000 single nucleotide polymorphism (SNP) loci and a targeted screen across 8 chromosomes with ∼3,300 SNPs was performed on 551 dogs (196 dogs were common to both sets). A mixed linear model approach was used to perform an association study on this combined association and linkage population. The study identified 4 susceptibility SNPs associated with HD and 2 SNPs associated with hip OA.

Conclusion/Significance

The identified SNPs included those near known genes (PTPRD, PARD3B, and COL15A1) reported to be associated with, or expressed in, OA in humans. This suggested that the canine model could provide a unique opportunity to identify genes underlying natural HD and hip OA, which are common and debilitating conditions in both dogs and humans.     

Factors affecting gestation duration in the bitch

A retrospective analysis was performed to determine the effects of age, breed, parity, and litter size on the duration of gestation in the bitch. Bitches at two locations were monitored from breeding to whelping. A total of 764 litters whelped from 308 bitches (36 large hounds, 34 Golden Retrievers, 23 German Shepherd Dogs (GSD), and 215 Labrador Retrievers). By breed, the number of whelpings was 152, 72, 58, and 482 for the hounds, Golden Retrievers, German Shepherd Dogs, and Labrador Retrievers, respectively. Whelping was predicted to be 57 d from the first day of cytologic diestrus in the hounds or 65 d from the initial progesterone rise in the other breeds. The average gestation duration (calculated as 8 d prior to Day 1 of cytologic diestrus in hounds or measured from the initial progesterone rise in other breeds) by breed (days +/- S.D.) was 66.0 +/- 2.8, 64.7 +/- 1.5, 63.6 +/- 2.1, and 62.9 +/- 1.3 for the hounds, Golden Retrievers, German Shepherd Dogs, and Labrador Retrievers, respectively. The relationship of age, breed, parity, and litter size with the difference in gestation duration was evaluated using log linear modeling. Age or parity had no effect on gestation duration. Compared to Labrador Retrievers, the German Shepherd Dogs, Golden Retrievers and hounds were more likely to have a longer gestation duration; three, four and nearly eight times as likely, respectively. Bitches whelping four or fewer pups were significantly more likely to have a longer gestation duration than those whelping five or more pups; the prolongation averaging 1 d.