C- AND G- BANDING PATTERNS AND CHROMOSOMAL MORPHOLOGY OF SOME BREEDS OF AUSTRALIAN CATTLE

A cytogenetical study using metaphase chromosomes from cultured lymphocytes, was made of 2 Banteng (Bibos banteng) steers and 218 bulls representing 13 purebreeds (Bos taurus type, Bos indicus type and Sanga) and 7 cross-breeds. Studies were made of photographic karyotypes of Giemsa stained and C-banded chromosomes of bulls of each breed and of B-banded chromosomes from 3 breeds of Bos indicus and one cross-breed Australian Friesian Sahiwal) cattle. The relative lengths of chromosomes of Bos taurus and Bos indicus bulls were compared and significant difference in relative lengths of the X chromosomes were noted between these two species. There was a differences in morphology of the Y chromosomes; Sanga, Banteng and Bos taurus type breeds had a small submetacentric Y chromosome, except for the Jersey which had a metacentric Y chromosome. All Bos indicus type bulls had an acrocentric Y chromosome but the Droughtmaster breed had two forms of the Y chromosome (submetacentric and acrocentric). The C-banding patterns of the autosomes and X chromosomes were similar for all breeds while those of the Y chromosomes of Bos indicus type cattle allowed their accurate identification. G-banding patterns of Bos indicus resembled those of Bos taurus and enabled pairing of homologous chromosomes. Centromeres of the autosomes were unstained but those of the sex chromosomes were darkly stained.     

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。     

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.     

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.     

马鹿染色体核型分析

采用常规细胞遗传学分析手段，对青海省西宁动物园饲养的马鹿染色体核型进行分析，结果：马鹿染色体数目为２ｎ＝６８，染色体臂数ＮＦ＝７０（♀）、７１（）；常染色体类型为２条中（Ｍ）着丝粒，６４条近端或端（Ａ）着丝粒；性染色体类型Ｘ为近端（Ａ），Ｙ为近中（ｓＭ）着丝粒；公母鹿核型式为６８，ＸＹ和６８ＸＸ。     

荒漠猫染色体的首次研究

采用外周血淋巴细胞培养和常规染色体制备分析技术，对青海省珍稀兽类荒漠猫染色体进行首次研究，结果显示：荒漠猫的染色体数目为２ｎ＝３８，常染色体形态类型为１０Ｍ＋１０ｓＭ＋１２ｓＴ＋４Ｔ（或Ａ），性染色体形态类型Ｘ为ｓＭ，Ｙ为ｓＴ，染色体总臂数ＮＦ＝７２，公母猫核型式为３８，ＸＹ和３８，ＸＸ。     

徐淮白山羊染色体核型研究1

采用外周血淋巴细胞培养及染色体分带技术分析了徐淮白山羊的染色体核型、C-带。结果表明，徐淮白山羊二倍体染色体数为2N=60，常染色体和X染色体均为端部着丝粒染色体．X染色体的大小介于1号和2号染色体之间，Y染色体最小．为中部着丝粒染色体，公羊核型为60．XY．母羊为60．XX。大部分常染色体和性染色体着丝粒部位显示阳性C带。     

草原红牛染色体核型与C带分析

采用外周血淋巴细胞短期培养及常规染色体标本制备技术,研究了草原红牛染色体核型及C显带,并着重分析了Y染色体的形态。结果表明:草原红牛二倍体细胞的染色体数目为2n=60,公牛为XY,母牛为XX,常染色体为端着丝粒染色体,X染色体为亚中部着丝粒染色体,Y染色体为中部着丝粒染色体。草原红牛C带带型特征与已报道的普通牛C带特征相一致:所有常染色体着丝粒区深染,常染色体臂和整个X染色体为浅染,Y染色体为半深染。     

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（♂）。     

Spermatogenesis in Bali cattle (Bos sondaicus) and hybrids with Bos indicus and Bos taurus

Semen quality, testis size and efficiency of sperm production in Bali cattle (Bos sondaicus) and hybrids with Bos indicus and Bos taurus were determined. Mean (+/- SEM) daily sperm production per gram of testis parenchyma (DSPG) in six purebred Bali bulls was 12.2 +/- 0.7 x 10(6). F1 B sondaicus cross B taurus bulls and F1 B sondaicus cross B indicus bulls were sterile. Spermatogenesis was arrested at the late primary spermatocyte stage. In 11 B sondaicus cross B indicus crosses, mean DSPG was lower than in the purebred B sondaicus, although four (one 1/4 B sondaicus, one 3/4 B sondaicus, one 5/8 B sondaicus inter se and one 3/8 B sondaicus inter se) exhibited DSPG levels similar to the foundation stock. Semen from those crossbreeds which exhibited complete spermatogenesis was more variable in terms of spermatozoal concentration, percentage of spermatozoa exhibiting progressive motility and levels of spermatozoal abnormalities. In crossbreeds where sperm production was reduced or absent, there was seminiferous epithelial dysfunction, manifested as an increased frequency of degenerative late pachytene and diplotene primary spermatocytes and germinal cells occurring later in the cycle, or in extreme cases, as complete arrest of spermatogenesis at the late primary spermatocyte stage.     

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 .     

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.     

科尔沁牛染色体14/24易位的初步研究

对内蒙古哲盟地区的5头科尔沁牛进行了细胞遗传学检查。结果:3♀和1♂核型全为2n=60,可配成30对,29对常染色体和1对性染色体,性染色体X为大型亚中着丝粒,Y为小型亚中着丝粒染色体;1♂的核型为异常核型,59,XY,t(14:24)。14/24易位是单独发生的。     

Genetic characterisation of the mithun (Bos frontalis) and studies of spermatogenesis, blood groups and haemoglobins of its hybrids with Bos indicus

The mithun (Bos frontalis) and its hybrids with Bos indicus were studied to provide further cytogenetic information which might throw light on the mechanisms of the male hybrid infertility and facilitate the establishment of a stable crossbreed. It was shown that compared with conventional cattle the mithun has a homozygous, species specific 2/27 centric fusion which reduced the diploid chromosome number from 60 to 58. This provided further proof that Robertson translocation-type rearrangements have been the major source of interspecies karyotype differences in the evolution of the Bovidae. In the mithun there was also significant polymorphism between centromeres of non-homologous chromosomes and there was heteromorphism between several homologous chromosomes which could possibly serve as useful genetic markers for breeding programmes. In F1 hybrids spermatogenesis progressed to a relatively advanced stage, without going so far as to produce spermatozoa. In back crosses to B indicus spermatogenesis progressed further so that spermatozoa could be seen, though not as numerous as in normal bulls. In most hybrids there were haemoglobin bands which corresponded either to Hb A or Hb B of cattle but were much wider. It was shown that these were a combination of Hb Mi derived from the mithun and Hb A or Hb B derived from B indicus. In a few hybrids there were only Hb Mi. In these cases Hb Mi had been present in both parents and proved that the dam was not a pure siri. The possible mechanism of hybrid male infertility is discussed including faults in the epistatic gene effect between chromosomes and changes in the degree of association of centromeric regions in interspecies hybrids. It is suggested that additional cytogenetic examination of blood lymphocytes and especially of testicles would help the understanding of the fertility barriers of hybrid males and would make a breeding programme for a stable crossbreed possible.     

哺乳动物Y染色体的测序进展

哺乳动物的性染色体由一对常染色体演化而来,其中X染色体在物种间相对保守,而Y染色体则存在很大的变异,包括染色体的大小、结构和基因数量等.研究Y染色体的遗传结构与变异,对于理解哺乳动物的起源进化、性别决定以及动物繁殖都具有重要意义.因此,文章综述了哺乳动物Y染色体的结构与变异,以及Sanger测序技术、二代测序技术、三代...     

Identification of the modifier locus that suppresses neonatal lethality in (♀DDD × ♂DH- Dh/+) F₁-Dh/+ male mice

Most F(1)-Dh/+ male mice resulting from a cross between inbred DDD strain females and DH-Dh/+ strain males exhibit growth retardation and die during the neonatal period. The lethality is caused by a combination of three independent gene loci, namely the Dh locus on chromosome 1, Grdhq1 locus on the X chromosome, and a putative Y chromosome-linked locus in some strains. Among these loci, Grdhq1 was previously mapped to a distal region of the X chromosome using progeny from♀(♀DDD × ♂DH-+/+) F(1) × ♂DH-Dh/+ mice. In this study, fine mapping of Grdhq1 was performed using progeny of ♀(♀DDD × ♂CAST/EiJ) F(1) ♂DH-Dh/+ mice. Contrary to expectation, Dh/+ male pups carrying the DDD allele at DXMit135 (genetic marker nearest to Grdhq1) survived to weaning. The presence of modifier loci that suppressed the lethality by impeding the action of Grdhq1 was suggested; therefore, a genome-wide scan was performed in the surviving Dh/+ males. As a result, a significant modifier locus was identified on proximal chromosome 11. This in turn suggested that Grdhq1 was located more distally than we had expected; that is, the actual location of Grdhq1 appeared to be near and/or distal to the Mid1 locus. Thus, the results revealed that the neonatal lethality in (DDD × DH-Dh/+) F(1)-Dh/+ males was caused by the fourth gene locus on chromosome 11 in addition to the above-mentioned three gene loci on chromosomes 1, X, and Y.     

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。     

Effect of breed of cattle on transmission rate and innate resistance to infection with Babesia bovis and B bigemina transmitted by Boophilus microplus

OBJECTIVE: To assess the effect of breed of cattle on the transmission rates of and innate resistance to Babesia bovis and B bigemina parasites transmitted by Boophilus microplus ticks. DESIGN: Groups of 56 purebred B indicus and 52 B indicus cross B taurus (50%, F1 generation) steers were placed in a paddock seeded with and also naturally infested with B microplus which were the progeny of females ticks fed on B taurus cattle specifically infected with a virulent isolate of B bovis. The cattle were placed in the infested paddock 50 days after seeding had started. PROCEDURE: Cattle were inspected from horseback daily for 50 days. Clinically ill cattle were brought to yards and assessed by monitoring fever, depression of packed-cell volume, parasitaemia and severity of clinical signs. Any animals that met preset criteria were treated for babesiosis. Blood samples were collected from all cattle on day 28, 35 and 42 after exposure and antibodies to Babesia spp and packed cell volume measured. RESULTS: All steers, except for one crossbred, seroconverted to B bovis and B bigemina by day 35 and 75% of the crossbred steers showed a maximum depression in packed cell volume of more than 15% due to infection with Babesia spp compared with only 36% of the B indicus group. Ten of the 52 crossbreds and 1 of the 56 B indicus steers showed severe clinical signs. Two of the crossbreds required treatment of which one died 2 weeks after initial treatment. CONCLUSIONS: Pure-bred B indicus cattle have a high degree of resistance to babesiosis, but crossbred cattle are sufficiently susceptible to warrant the use of preventive measures such as vaccination. Transmission rates of B bovis and B bigemina to B indicus and crossbred cattle previously unexposed to B microplus were the same.     

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.