Y CHROMOSOME MORPHOLOGY OF CATTLE

Metaphase chromosomes from cultured lymphocytes were prepared from 246 bulls including Bos indicus, Bos taurus. Bos (Bibos) banteng, Sanga and interspecific and intra-specific breed crosses. Morphology and karyotype position of the Y chromosome for each bull were noted. Karyotype position of the Y chromosome varied between bulls from 25th to 29th pair and the Y chromosomes of Bos indicus and breeds derived from Bos indicus bulls were acrocentric while those of Bos taurus, Sanga and breeds derived from these bulls were metacentric/submetacentric. Two forms of Y chromosome were noted in the Droughtmaster breed. C-banding patterns of the acrocentric Y chromosome were characteristic and enabled easy identification.     

秦川牛的染色体研究

对秦川牛(12♂,3♀)染色体的核型、G带、C带及Ag-NOR_s的研究表明:秦川牛品种内Y染色体存在多态现象,Y染色体有中、亚中和近端着丝点染色体。中和亚中着丝点Y染色体G带和C带与普通牛(Bos taurus)相同,近端着丝点Y染色体G带和C带与瘤牛(Bos indicus)相同。根据Y染色体多态性,讨论了秦川牛起源的多元性。统计了2002个细胞的Ag-NOR_s数目,每细胞Ag-NOR_s数变化范围3～10个,平均5.473±0.316。     

Chromosomes of gaur cross domestic cattle hybrids

The chromosomes of five gaur (Bos gaurus hubbacki) domestic cattle (B indicus cross B taurus) hybrids (three females, two males) were studied using the leucocyte culture method and centromeric (C) banding technique. All the hybrids had a diploid chromosome number of 2n = 58, made up of two submetacentric autosomes (different in size) and 54 acrocentric autosomes, most of which could be arranged in pairs in descending order of size. The sex (X) chromosomes in females were a pair of submetacentric chromosomes smaller than the submetacentric autosomes. The Y chromosome in males was a small submetacentric chromosome. The C banding patterns were useful in identifying the X and Y chromosomes and the inherited submetacentric autosomes from the gaur sire. Phenotypically, the hybrids resembled normal B indicus cross B taurus calves except for the presence of a distinct hump-like dorsal ridge containing the spinous processes of the third to 11th thoracic vertebrae, upright 'deer-like' ears and long lean legs. The potential of these hybrids as important genetic resources for meat production is stressed.     

Bos taurus Y chromosome of Africander cattle and the development of improved breeds for the tropics.

The Africander has anatomical and other characteristics of an animal of approximately 3/4 Bos indicus heredity. The fact that these cattle carry the Bos taurus Y chromosome supports this view and indicates that the local cattle in South Africa would have been crossed with one or more Bos taurus bulls. Droughtmaster and Braford cattle retain the Bos indicus Y chromosome because Bos indicus instead of Bos taurus bulls were used to establish these taurindicus breeds. Contrary to some assumptions, an approximate tenfold increase in productivity of cattle was made during the 18th and 19th centuries due to improvements in disease control, nutrition and genetic improvement. What is now needed is the development of taurindicus breeds combining to the maximum possible extent the disease resistance and hardiness of Bos indicus with the early maturity and productivity of Bos taurus cattle. In addition, the ravages of disease and the seasonal variations of food supply need to be overcome in tropical areas.     

中国黄牛Y-STRs遗传多样性与起源研究

[目的]研究中国黄牛Y染色体STRs的遗传多样性及父系起源。[方法]利用非变性聚丙烯酰胺凝胶电泳,选择2个牛Y-STRs位点INRA189和BM861,分析16个中国地方黄牛品种284头公牛与4头缅甸黄牛公牛的Y染色体遗传多样性。[结果]在中国16个黄牛品种中,2个Y-STR位点可以区分中国黄牛中的普通牛和瘤牛类型,表明中国黄牛有普通牛和瘤牛两种父系起源。4头缅甸黄牛均为瘤牛类型。在中国16个黄牛品种中,普通牛和瘤牛分布频率分别为57.0%和43.0%,其中普通牛频率在北方黄牛中占优势(98.3%),瘤牛频率在南方黄牛中占优势(76.1%),中原黄牛中普通牛频率较高为63.8%,瘤牛频率为36.2%。[结论]中国黄牛存在普通牛和瘤牛两种父系起源;普通牛频率自北向南逐渐减少,瘤牛频率自北向南逐渐增加,中原地区为普通牛和瘤牛的交汇处。     

A Cytogenetic Investigation of Madura Cattle

Contents: " Madura cattle," the variety found on the Indonesian island of Madura, is most often referred to as a cross between Bos javanicus and Bos indicus, based largely on phenotypic appearance. The karyotypic patterns of Madura cattle resemble those of Bos taurus, with the exception of the Y chromosome, which is of Bos indicus type. Based on what is known of Bos javanicus, it is concluded that Madura cattle could be the result of a cross between a Bos taurus or Bos javanicus cow and a Bos indicus bull .
Inhalt: Eine cytogenetische Untersuchung über das Madura-Rind
Das Madura-Rind, eine Varietät der indonesischen Insel Madura, wird wegen seines Aussehens oft als Kreuzung zwischen Bos javanicus ( Banteng) und Bos indicus ( Zebu) angesehen. Das karyotypische Bild des Madura-Rindes gleicht jenem von Bos taurus mit Ausnahme des Y-Chromosoms, welches dem Bos indicus- Typ entspricht. Nachdem, was über Bos javanicus bekannt ist, muβ man folgern, daβ das Madura-Rind ein Kreu-zungsprodukt zwischen einer Bos taurus- oder Bos javanicus-Kuh und einem Bos indi- cusBullen sein könnte .     

中国黄牛Y-SNPs遗传多样性与起源研究

为了研究中国黄牛Y染色体SNPs的遗传多样性及父系起源,本研究利用PCR-SSCP与测序方法,选择4个牛Y-SNPs位点DDX3Y-7、UTY-19、ZFY-9和ZFY-10,分析了16个中国地方黄牛品种284头公牛与缅甸黄牛4头公牛Y染色体的遗传多样性.结果表明,在中国16个黄牛品种中,仅发现普通牛Y2和瘤牛Y3单倍型,表明只有Y2和Y3两种父系起源,尚未发现中国黄牛存在普通牛Y1单倍型的分子证据.4头缅甸黄牛均为Y3单倍型.在中国16个黄牛品种中,Y2和Y3单倍型频率分别为57.0％和43.0％,其中Y2单倍型频率在北方黄牛中占优势(98.3％),Y3单倍型频率在南方黄牛中占优势(76.1％),中原黄牛中普通牛Y2的单倍型频率较高,为63.8％0,瘤牛Y3的单倍型频率为36.2％.本研究证明,中国黄牛存在普通牛Y2和瘤牛Y3单倍型两种父系起源,Y2单倍型频率自北向南逐渐减少,Y3单倍型频率自北向南逐渐增加,中原地区为普通牛Y2和瘤牛Y3单倍型的交汇处.     

The effect of the brown ear-tick Rhipicephalus appendiculatus on the growth of Sanga and European breed cattle

The effects of larvae, nymphs and adults of the brown ear-tick Rhipicephalus appendiculatus on the growth of Bos indicus X B. taurus (Sanga) steers and on B. taurus steers and heifers was measured by exposing groups, maintained in the same pastures, to different levels of tick challenge. Larvae and nymphs had no significant effect on liveweight gains, but adults had a large effect. Each engorging female tick counted was associated with a loss of 4 g. Their effect on the Sanga cattle was minimised by host resistance which severely limited the number of ticks feeding on them. The B. taurus animals were severely affected and suffered extensive ear damage. Both breeds were subjected to screw-worm fly (Chrysomya bezziana) strike in the lesions caused by heavy tick infestations, but the B. taurus animals were much more prone to attack. The results provide a basis for calculating losses in production caused by this species of tick which is widespread in Africa.     

南宁市肉牛的Y染色体遗传多样性分析

[目的]为了探究广西南宁市肉牛的父系遗传背景与遗传组成。[方法]利用PCR扩增、限制性酶酶切和生物信息学方法,对南宁屠宰场的73头肉牛Y染色体USP9Y基因的遗传多态性进行分析。[结果]发现73头公牛USP9Y基因的PCR产物具有多态性,2头牛显示471 bp带型,71头牛显示552 bp带型。在71个552 bp带型中,有28个可以被SspI酶切成2条带(338 bp和215 bp),表明这28头牛为Y3单倍型组(38.36%),而其余43个不能被SspI酶切,表明这43头牛为Y2单倍型组(58.90%)。仅有2头牛的PCR产物为471 bp,表明这2头牛为Y1单倍型组(2.74%)。屠宰牛群的单倍型多样度为0.5122±0.0309,表明屠宰牛群的Y染色体遗传多样度较高。[结论]南宁市屠宰牛群的来源比较复杂,有普通牛(Y1与Y2单倍型组)和瘤牛(Y3单倍型组)2个父系起源。     

A note on the somatic Y chromosome of reindeer (Rangifer tarandus L.)

Recently a report on the reindeer chromosomes was published (Nes et al. 1965). The chromosome complement was described as consisting of 70 autosomes and a sex chromosome set of the XY-type. All autosomes were acrocentric except one pair which was submetacentric. The X was found to be submetacentric and also the largest chromosome of the complement. The Y was characterized as being the smallest acrocentric chromosome, and the authors stated that the Y chromosome could only occasionally be distinguished from the autosomes by its shorter length.In our studies of the same species we have found a quite different appearance concerning the Y chromosome.     

闽南牛遗传多样性及其系统地位的研究

以中心产区简单随机抽样法在福建省漳州市漳浦县霞关乡抽取闽南牛64头,采集血样,按常规方法分离血浆和血细胞,冷冻后带回实验室-20℃保存备用。用垂直平板聚丙烯酰胺凝胶电泳(PAGE)和水平淀粉凝胶电泳技术检测21个编码血液蛋白(酶)的结构基因座的基因频率,同时引用国内外13个群体7个相同座位的研究资料,进行聚类分析,结果表明:在所检测的21个基因座中,有10个存在多型,多态位点百分比为47．62％,群体内遗传变异水平相对较高,平均杂合度为0．1593;闽南牛与东南亚牛种亲缘关系较近,证实了闽南牛是由南方黄牛和瘤牛的混血种,但可能不含有斑腾牛或巴厘牛的血统。目前应扩大保种群的数量,以维持群体内遗传传多样性。     

Presumptive 1/29 autosomal translocation in Australian cattle.

A cytogenetical study was made of 9 descendants of a Charolais bull, heterozygous for a presumptive 1/29 translocation, three of the dams of some of these descendants, and three unrelated bulls which were mated to some of the descendants. Photographic karyotypes of Giemsa stained and C-banded chromosomes were prepared for each animal. The dams of the progeny showed no chromosomal abnormalities indicating that translocations were inherited from the sire. Three daughters of the Charolais bull and two of his grand daughters were heterozygous for the translocation, with a modal chromosomal number of 59, while the remaining three daughters and their progeny possessed normal karyotypes. No phenotypic abnormalities were observed in the animals examined. Measurements of the arms of the chromosomes suggested that the translocation chromosome (a large submetacentric) contained chromosomes 1 and 29. The submetacentric translocation chromosome had a single C-band, the two submetacentric X chromosomes showed no C-bands and each acrocentric autosome had a single C-band. All cattle heterozygous for the translocation showed normal fertility.     

Calving and weaning characteristics of Angus-, Gray Brahman-, Gir-, Indu-Brazil-, Nellore-, and Red Brahman-sired F1 calves

Calving and weaning data from crossbred calves sired by five Bos indicus breeds and one Bos taurus breed were evaluated. Data included calving and weaning records of F1 calves out of multiparous Hereford cows and sired by Angus, Gray Brahman, Gir, Indu-Brazil, Nellore, and Red Brahman bulls. At calving, Angus-sired calves had shorter gestations and lower (more desirable) calving ease scores and were smaller than Bos indicus-sired calves. Among the Bos indicus crosses, Gir calves had the shortest gestations, lowest calving ease scores, lightest birth weights (P less than .05), and smallest cannon bone lengths and heart girths. Nellore calves had the longest gestations (P less than .05) and largest heart girths. Calves by Indu-Brazil sires had the highest calving ease scores, highest birth weights (P less than .05), and greatest cannon bone lengths (P less than .05). Gray Brahman- and Red Brahman-sired calves were similar and intermediate for all calving characters. At weaning, Angus-sired calves had gained slightly faster than the Gir crosses and weighed more but were shorter at the hip than Gir crosses. Gir calves gained the least preweaning, weighed the least, and were shortest at weaning of the Bos indicus crosses. The Nellore and Indu-Brazil crosses were intermediate in preweaning gain and weaning weight to the Gir and the Red and Gray Brahman but were tallest at weaning. Gray Brahman and Red Brahman calves gained the most and were heaviest at weaning but were not as tall as the Nellore and Indu-Brazil.     

Comparative Histology of the Kidney of Bos taurus and Bos indicus Cattle

Twenty-six kidneys of 2–4 years old Bos indicus (zebu cattle) and twenty kidneys of 4-year old Bos taurus were examined under the light microscope. The renal tubular epithelial heights and diameters were smaller in zebu than in Bos taurus. The Bos indicus kidney had fewer vascular bundles in the outer medullary zone and a smaller number of capillaries per vascular bundle, hence a lower renal blood flow than in Bos taurus. The Bos indicus proximal tubules had broader brush borders than those of Bos taurus. The smaller renal corpuscles with smaller glomerular filtration surface and low renal blood flow are responsible for low glomerular filtration rate and urinary flow, enabling their kidneys to retain more water than those of Bos taurus.     

Karyotypes of three shrew species (Soriculus nigrescens,Episoriculus caudatus and Episoriculus sacratus) from Nepal

The karyotypes of three shrew species (Mammalia, Soricomorpha, Soricidae) from Nepal were examined for the first time. Based on the karyotypes and overall differences in skull size, the current Episoriculus caudatus appeared to include two distinct species: the larger E. caudatus and the smaller Episoriculus sacratus. Episoriculus sacratus has three subspecies, E. s. soluensis in Nepal and Sikkim, E. s. umbrinus in Assam, Myanmar and the Yunnan Province of China, and E. s. sacratus in the Sichuan Province of China. Soriculus nigrescens had a diploid chromosome number (2n) and fundamental number (FN), including two X chromosomes, of 64 and 92, respectively, consisting of 11 metacentric or submetacentric, two subtelocentric and 18 acrocentric pairs of autosomes, a metacentric X and an acrocentric Y chromosome. Episoriculus sacratus soluensis had 2n = 74 and FN = 126, consisting of 12 metacentric or submetacentric, 13 subtelocentric and 11 acrocentric pairs of autosomes, a submetacentric X and an acrocentric Y chromosome. Episoriculus caudatus had 2n = 60 and FN = 118, consisting of 19 metacentric or submetacentric, nine subtelocentric and one acrocentric pair of autosomes, a subtelocentric X and an acrocentric Y chromosome. The karyotypes of these three species are characterized by their large 2n and FN values compared with other Soricidae.     

Susceptibility of Bos indicus and Bos taurus to Anaplasma marginale and Babesia bigemina infections

The reaction of Bos taurus and pure-bred Bos indicus heifers to infection with the intraerythrocytic parasites Anaplasma marginale and Babesia bigemina was studied. B. bigemina infection at 18 months and A. marginale infection at 13 or 24 months resulted in slightly less severe reactions in pure-bred Bos indicus cattle than in Bos taurus. In both breeds, the reaction to A. marginale infection was more severe in older cattle. The severity of B. bigemina infection was not affected by a previous infection with A. marginale.     

Detection of chromosome segments of zebu and taurine origin and their effect on beef production and growth

Cattle in breeds formed by recent crossing of Bos taurus (Bt) and Bos indicus (Bi) subspecies should contain chromosomes that are a composite of Bt and Bt segments. Using data from a 50K SNP chip, we were able to identify whether a chromosome segment of 11 SNP in a composite animal descended from a Bt or a Bi ancestor. When the method was tested in purebred Bt or Brahman cattle, about 94% of segments were assigned correctly. About 10% of the genome in Australian Brahman cattle appears to be of Bt origin, as might be expected from their history. We then examined the effect of the origin of each chromosome segment on BW in a population of 515 Bt × Bi composite cattle and found 67 chromosome segments with a significant (P<0.01) effect. We confirmed these effects by examining these 67 segments in a population of Brahman cattle and in a population of mixed breeds including composite breeds such as Santa Gertrudis and Brahman cattle. About 66% of the 67 segments had an effect in the same direction in the confirmation analyses as in the discovery population. However, the effect on BW and other traits of chromosome segment origin is small, indicating that we had low power to detect these effects with the number of animals available. Consequently, when chromosome segment origin was used in genomic selection to predict BW, the accuracy was low (0.08). Chromosome segments that had a positive effect on BW tend to be at greater frequency in composite breeds than chromosome segments with a negative effect on BW.     

哈白兔×日本大耳兔F1的染色体核型分析

采用常规细胞遗传学手段,对青海省畜牧兽医科学院饲养的哈白兔×日本大耳兔Ｆ１的染色体核型进行分析,结果表明,Ｆ１的染色体数目２ｎ＝４４,染色体臂数ＮＦ＝７８（♂）;常染色体类型１～７对为中着丝粒染色体（Ｍ）,８～１０对为亚中着丝粒染色体（ＳＭ）,１１～１６对为近端着丝粒染色体（ＳＴ）,１７～２１对为端着丝粒染色体（Ｔ）,性染色体Ｘ为亚中着丝粒染色体（ＳＭ）,Ｙ为中着丝粒染色体（Ｍ）,公兔核型式为４４,ＸＹ（♂）。     

Variations in the Length of the Y Chromosome and the Seminal Attributes of Karan Fries Bulls

Fresh semen and blood samples from 20 Karan Fries bulls (4–6 years of age), maintained at the Artificial Breeding Complex of the National Dairy Research Institute, Karnal, were collected for one year. All the bulls had 60 chromosomes, comprising 58 acrocentric autosomes and 2 sex chromosomes, with X as the larger and Y as the smaller submetacentric. The mean lengths of Y_p and Y_q; the total length of the Y chromosome and the length ratio were 1.10±0.01 m, 1.83±0.02 m, 2.92±0.02 m and 62.46%±0.18%, respectively. Analysis of the length measurements of the the Y chromosomes in Karan Fries bulls showed that all the measurements, viz., the short arm of the Y chromosome, the long arm of the Y chromosome, the total length of the Y chromosome and the variation in length of Y chromosome, varied significantly among bulls. All the seminal parameters, the volume of semen, mass activity, initial motility, concentration, live sperm count and the total abnormal sperm count, were significantly affected by bulls, whereas season had a significant effect on all the seminal parameters except the total abnormal sperm count. No significant relationship between the ratio of the long arm to the total length of the Y chromosome and seminal attributes was observed.     

贵州黎平黄牛线粒体DNA D-loop区全序列初步分析

为了解贵州黎平黄牛的遗传多样性及遗传背景,我们测定了20头黄牛的线粒体DNA D-loop区序列。结果检测到8种单倍型,其中4种为普通牛血统的单倍型,4种为瘤牛血统的单倍型,表明黎平黄牛同时受普通牛和瘤牛的影响。该研究对于黎平黄牛的保种及持续利用有着重要的理论指导意义。