山羊草属杀配子染色体2C特异SCAR标记的建立

用40条10碱基随机引物,对普通小麦“中国春”、“中国春”-杀配子染色体2C二体附加系、柱穗山羊草进行RAPD分析,筛选到1个杀配子染色体2C特异引物OPF03。从“中国春”-杀配子染色体2C二体附加系中克隆了该DNA片段。测序结果表明,该片段长1 496 bp,与大麦1个cDNA的同源性为92%。根据OPF03₁₄₉₆的序列设计了1对SCAR引物2C-F₅₈₆、2C-R₅₈₆,对普通小麦“中国春”、“中国春”-杀配子染色体2C二体附加系、柱穗山羊草、二倍体长穗偃麦草、“中国春”-长穗偃麦草7E二体附加系等材料进行了SCAR分析,在“中国春”-杀配子染色体2C二体附加系、柱穗山羊草中扩增出了586 bp的片段,而在普通小麦“中国春”、二倍体长穗偃麦草、“中国春”-长穗偃麦草7E二体附加系中没有该产物,初步证明此标记可以用于杀配子染色体2C的检测。进一步用该对SCAR引物对“中国春”-杀配子染色体2C二体附加系与“中国春”-长穗偃麦草7E二体附加系的杂种F₁代、F₂代进行了分析,结果在全部F₁代以及部分F₂代材料扩增出了目的片段,进一步证明了此SCAR标记可以用来检测小麦背景下的杀配子染色体2C,为小麦背景中杀配子染色体2C的快速跟踪检测提供了新途径。     

Putative quantitative trait locus affecting birth weight on bovine chromosome 2

A genome scan for chromosomal regions influencing birth weight was performed using 151 progeny of a single Hereford x composite bull and 170 microsatellite markers spanning 2.497 morgans on 29 bovine autosomes. A QTL was identified at the telomeric end of bovine chromosome 2 (maximum effect at 114 cM) accounting for approximately 2.8 kg of birth weight or 0.64 residual standard deviations (after adjustment for sex of calf, age of dam, and breed of dam). No significant effect on growth from birth to weaning was detected in this region. The presence of this QTL within a resource herd composed of breeds common to the Northern Great Plains provides an opportunity to initiate marker-assisted selection to reduce birth weight with minimal effect on postnatal growth. Thus, potentially the amount and degree of dystocia can be reduced and the economic loss associated with calving difficulty lessened without compromise of subsequent growth performance. In addition, this finding indicates that significant genetic variation for birth weight (and presumably other production-related traits) exists within herds composed of commercially adapted Bos taurus germplasm.     

染色体技术研究进展

染色体是生物遗传的物质载体，在生物的世代相传过程中表现出高度的稳定性和物种特异性，本文就染色体技术的发展历程及染色体制备分析技术进行了综述。     

Loci on Bos taurus chromosome 2 and Bos taurus chromosome 26 are linked with bovine respiratory disease and associated with persistent infection of bovine viral diarrhea virus

The objective of this study was to identify loci linked with bovine respiratory disease (BRD) and subsequently to determine if these same loci were associated with bovine viral diarrhea virus persistent infection (BVD-PI) in affected calves or their dams. A genome-wide linkage study using 312 microsatellites was conducted to identify loci linked with BRD in a Brahman × Hereford sire half-sib family. Disease incidence was recorded from birth to slaughter by daily monitoring. Linkage was suggestive for a QTL on BTA2 (F = 7.31, P = 0.007) and BTA26 (F = 10.46, P = 0.001). Six and 7 markers were added and genotyped between 110 and 126 cM on BTA2 and between 42 and 72 cM on BTA26, respectively, in the intervals where linkage was found. These markers were used to reevaluate the Brahman × Hereford family and to evaluate 3 additional crossbred half-sib families. Linkage was found with BRD on BTA2 (F = 4.94, P < 0.01), with a peak at 110 cM, and on BTA26 (F = 4.03, P < 0.05), with peaks at 42 and 52 cM. The same markers were then tested for an association with BVD-PI in 1) BVD-PI calves compared with age-matched unaffected calves from the same herd or 2) dams with BVD-PI compared with age-matched unaffected calves. Sixty commercial beef cow-calf herds were tested for BVD-PI, and 79 calves from 8 ranches had BVD-PI. Four of 6 markers were associated (P = 4.8 × 10(-9) to P = 0.01) with BVD-PI on BTA2, and 4 of 7 markers were associated (P = 0.008 to P = 0.04) with BVD-PI on BTA26 when BVD-PI calves were compared with unaffected calves. The comparison of BVD-PI dams with unaffected calves detected associations with BVD-PI for all markers tested on BTA2 (P = 3 × 10(-9) to P = 0.005) and for 3 of 7 markers on BTA26 (P = 1.4 × 10(-6) to P = 0.006).     

Infertile mares with chromosome abnormalities

Chromosomal abnormalities have been detected in five mares identified by their poor reproductive performance. All had small gonads and absent or irregular oestrous cycles. One mare was 65, XXX, two were 64, XY sex-reversal females and two were sex chromosome mosaics with karyotypes of 63, XO/64, XX/64, XY and 63, XO/64, XX respectively. This report supports the suggestion made in earlier studies that sex chromosome abnormalities may be a significant cause of sterility in the mare.     

Evaluation of FABP2 as candidate gene for a fatty acid composition QTL in porcine chromosome 8

The objective of this work was to analyse the porcine Fatty acid binding protein 2, intestinal ( FABP2 ) gene as a candidate gene for a fatty acid composition quantitative trait loci (QTL) previously described on porcine chromosome 8 in an Iberian by Landrace F₂ cross (IBMAP). Re-sequencing of the porcine FABP2 gene in three Iberian and eight Landrace parental animals resulted in the identification of three single-nucleotide polymorphisms, all of them localized in intron 1. The polymorphism FABP2 :g.412T>C, localized in intron 1, and two additional microsatellites were genotyped in the IBMAP population in order to perform an association test of the FABP2 gene and to better define the QTL position previously described. Association analyses of the FABP2 :g.412T>C with the fatty acid composition traits were not significant in simple association and marker-assisted association tests, suggesting that the FABP2 region sequenced is not responsible for the QTL. However, the addition of three new markers to the pedigree allowed us to define the S0144–SW61 marker interval as the most likely QTL position, facilitating the future study of other candidate genes for this QTL.     

几种早熟禾及其人工杂种染色体数目变化的特异性

通过对3个草地早熟禾品种莫诺波利、瓦巴斯、恩托佩和变种扁秆早熟禾及其人工杂种染色体的观察计数，指出每种早熟禾染色体数没有一个固定的值，而是一个变化范围，有1－2个众数，基本上是以7为基数变化的，同时对这种变化的遗传基础进行了分析探讨。     

家鸡染色体研究进展

近年来,由于现代分子细胞遗传学技术,尤其是荧光原位杂交(FISH)技术的出现,使家鸡的染色体研究又进入了一个新的高潮.作者从家鸡染色体核型研究简史、显带研究及其现代分子细胞遗传学研究3个方面对家鸡染色体研究进展作一概述,旨在对其有一较系统全面的了解,以促进其进一步研究,并为其它禽类的染色体研究提供参考.     

Monitoring chromosome mutations in large-scale breeding operations

The frequency of chromosomal aberrations and exchanges of sister chromatids (SCEs) in peripheral lymphocytes was studied in 65 pigs from five large breeding herds. Four groups comprised fattened pigs and the fifth group consisted of sows from a large multiplier breeding herd. During the investigation, the dust from the sites was analyzed for the presence of zinc, lead, cadmium, mercury, aflatoxin B1, PCB, DDT, and lindane. The average frequency of aberrant cells (AB.B) in the pigs of group I was 3.85 +/- 1.60%, in group II 2.10 +/- 1.52%, in group III 5.01 +/- 2.1%, in group IV 3.50 +/- 1.58%, and in group V 6.20 +/- 3.21%. The cytogenetic finding corresponded to the differences in the amount of foreign substances found in the dust on the premises where the animals of all groups were kept. The average frequency of the SCEs was 7.00 +/- 1.10 (I), 6.51 +/- 0.89 (II), 6.92 +/- 0.72 (III), 7.10 +/- 0.85 (IV) and 7.06 +/- 1.47 (V) per one cell. Statistically significant differences in the numbers of AB.B. were recorded between groups II and I, II and IV, I and III, IV and V (p less than 0.05) and between groups II and III, II and V (p less than 0.01). There was no statistically significant difference in the frequency of SCEs. The determination of the frequency of chromosomal aberrations can be used for the hygienic control of the degree of exposure of pigs to mutagens.     

毛稃偃麦草染色体核型分析

采用根尖压片法对毛稃偃麦草的细胞染色体进行核型分析。结果表明毛稃偃麦草（Elytri-gia alatavica）染色体数目为2n=42,染色体相对长度组成为12L＋4M2＋14M1＋12S,核型公式K（2n）=6 X=42=36m＋6sm（2sat）,属于＂1B＂类型。其中,3对为近中着丝粒染色体,且带有1对随体,其...     

Further cases of equine sex chromosome abnormalities

Sex chromosome abnormalities have been detected in a further five mares with clinical histories of small ovaries and absent or irregular oestrous cycles. Three mares had 63,XO karyotypes (X monosomy) and two were sex chromosome mosaics with karyotypes of 63,XO/64,XY and 63,XO/64,XX/64,XY respectively. A sex chromosome abnormality (X monosomy) has also been found in a filly where it was suspected because of her short stature.