Genetic variants affecting meat and milk production traits appear to have effects on reproduction traits in cattle

Polymorphisms located in the genes ABCG2, DGAT1, LEP, PRLR, RORC, CAPN1 and CAST previously have been associated with milk or meat production traits. In this study, these polymorphisms were examined for significant effects on reproductive traits [age at puberty (AGECL), post-partum anoestrus interval (PPAI) and the ability ovulate prior to weaning (PW)] and on a panel of correlated traits such as weight, growth and serum concentration of insulin-like growth factor I. The effects of the polymorphisms were examined in two samples of tropically adapted beef cattle: Brahman (N = 932) and Tropical Composites (N = 1097). A polymorphism in the gene DGAT1 was associated with age at puberty in the combined sample (P = 0.042), and two polymorphisms in CAPN1 were associated with PPAI (P = 0.033) and with the ability ovulate PW (P = 0.017). The favourable allele for reproductive traits was not always the favourable allele associated with production traits. The effects of these polymorphisms on reproductive traits were small compared to their effects on the traits for which they were originally discovered.     

蝘蜓消化管内分泌细胞的免疫组织化学定位

目的阐明爬行动物蝘蜓消化管各段内分泌细胞的类型、局部分布、分布密度和形态学特征。方法应用免疫组织化学技术中链霉卵白素-过氧化物酶(S-P)法。结果在蜓消化管内鉴别出5种内分泌细胞,即:5-羟色胺(5-hydroxytryptamine,5-HT)、生长抑素(somatostatin,SS)、胃泌素(gastrin,GAS)、高血糖素(glucagon,GLU)、P-物质(substance P,SP)免疫活性(i mmnoreactive,IR)细胞。5-羟色胺免疫活性细胞是消化管中最主要的内分泌细胞类型,以不同密度分布于消化管各段,其中胃幽门部位分布密度最高。生长抑素免疫活性细胞在消化管内仅局限分布于胃部。胃泌素免疫活性细胞仅见于幽门和十二指肠部位。高血糖素免疫活性细胞仅分布于回肠和直肠。P-物质免疫活性细胞仅出现在直肠部位。蝘蜓消化管内分泌细胞形态多样:圆形、椭圆形、纺锤形、梭形、楔形、锥形以及不规则形。胃部多数内分泌细胞分布于胃腺中,食管和肠管中多数内分泌细胞则分布于上皮细胞间。结论蜓和其它爬行动物胃肠内分泌细胞的分布存在一定共同特征,然而也存在着一些特有的差异。     

基于数字地形模型的斑头雁潜在生境分析

建立了青藏高原地区的数字地形模型,并将其应用在斑头雁(Anser indicus)的潜在生境提取与分析中。通过数字高程模型、水系模型、湖泊及环湖活动区模型和植被模型的GIS叠置,提取了斑头雁的潜在生境,并对来自青海湖的11只斑头雁的卫星跟踪数据进行了验证分析。结果表明,斑头雁的潜在生境(湖泊与环湖活动区构成)共有275处(以湖泊为单位),湖泊水体总面积约为10306.4km2,59处生境已验证有斑头雁停留的踪迹,其中部分湖泊周围的验证点可能是斑头雁飞行时的定位点而不是停留定位点,目前还无法证实。繁殖地、迁徙停留地和越冬地比较集中,迁徙路线较固定。     

The IGF1 pathway genes and their association with age of puberty in cattle

Insulin‐like growth factor I (somatomedin C) (IGF1) influences gonadotrophin‐releasing hormone (GnRH) neurons during puberty, and GnRH release guides pubertal development. Therefore, genes of the IGF1 pathway are biological candidates for the identification of single‐nucleotide polymorphisms (SNPs) affecting age of puberty. In a genome‐wide association study, genotyped heifers were Tropical Composite (TCOMP, n = 866) or Brahman (BRAH, n = 843), with observation of age at first corpus luteum defining puberty. We examined SNPs in or near genes of the IGF1 pathway and report seven genes associated with age at puberty in cattle: IGF1R, IGFBP2, IGFBP4, PERK (HUGO symbol EIF2AK3), PIK3R1, GSK3B and IRS1. SNPs in the IGF1 receptor (IGF1R) showed the most promising associations: two SNPs were associated with puberty in TCOMP (P < 0.05) and one in BRAH (P = 0.00009). This last SNP explained 2% of the genetic variation (R² = 2.04%) for age of puberty in BRAH. Hence, IGF1R was examined further. Additional SNPs were genotyped, and haplotypes were analysed. To test more SNPs in this gene, four new SNPs from dbSNP were selected and genotyped. Single SNP and haploytpe analysis revealed associations with age of puberty in both breeds. There were two haplotypes of 12 IGF1R SNPs associated with puberty in BRAH (P < 0.05) and one in TCOMP (P < 0.05). One haplotype of two SNPs was associated (P < 0.01) with puberty in BRAH, but not in TCOMP. In conclusion, the IGF1 pathway appeared more relevant for age of puberty in Brahman cattle, and IGF1R showed higher significance when compared with other genes from the pathway.     

Influence of acute salinity changes on biochemical,hematological and immune characteristics of Fenneropenaeus indicus during white spot syndrome virus challenge

The present study reports the influence of salinity (5, 15, 25 and 35 g/L) on the biochemical and immune characteristics of Fenneropenaeus indicus challenged with 5. 5 × 10⁴ copy number of white spot syndrome virus (WSSV). F. indicus that had been reared in 25 g/L, injected with WSSV and transferred to 5, 15, 25 (control) and 35 g/L were examined after 0–120 hrs for total hemocyte count (THC), phenoloxidase (PO) and respiratory burst (RB) activity and alkaline and acid phosphatase activities. It was concluded that F. indicus that had been transferred from 25 g/L to lower and higher salinity levels (5, 15 and 35 g/L) had poorer immune indices and decreased resistance against WSSV infection. After 120 hrs, the mortality rate in WSSV‐injected F. indicus experimental groups (5 and 35 g/L) was significantly higher than for F. indicus exposed to 25 and 15 g/L salinities. During the experimental period (0–120 hrs), biochemical variables, namely total protein, carbohydrate, and lipid concentrations, were measured in hemolymph of both experimental and control groups. Acute salinity changes induced an increase in protein variations across the tested salinity ranges in shrimp. After 24 hrs, THC and PO activity decreased significantly whereas RB, alkaline phosphatase and acid phosphatase activities increased in shrimps kept at the lower salinities of 5, 15 and 35 g/L.     

Phenotypic selection of Brahman bulls: Adaptive typification for breeding programs

The purpose of this study was to evaluate the relationship between adaptive and productive performance and determine which characteristics related to adaptation could be included as criteria for the selection of Brahman bulls managed in a tropical region. Fifty Brahman bulls were evaluated in relation to productive performance and adaptive capacity to a hot environment. The animals were grouped according to the following characteristics: Respiratory rate (RR), Sweating rate (SR) and coat traits. Three clusters were formed with these different characteristics related to thermoregulation after that these clusters were compared with productive performance that includes weighing of animals, carcass and scrotal circumference. The high adapted group corresponded to the animals with higher productive performance, with heavier animals in terms of weight at 550 days and carcass weight. The principal components analysis (PCA1) showed that carcass weight (0.95), weight at 550 days (0.92) and gain weight (0.71) were characteristics strongly correlated with the performance of the animals. These sets of characteristics were analyzed together (productive characteristics) in a multiple regression. The animals with better productive performance presented shorter hair, a greater capacity to heat dissipate by sweating and a lower rectal temperature. These characteristics were most suitable to inclusion in the breeding programs, resulting in higher economic gains. It is possible to simultaneously select resistant animals to thermal stress as well as to maintain the productivity of the flocks.     

Changes in Nightjar Caprimulgus europaeus populations in upland forests in Yorkshire

The Nightjar populations of Yorkshire's upland forests have grown significantly during recent years, probably as a result of a concurrent increase in the available area of suitable habitat due to forest management. In common with other populations it appears that the birds utilize younger, more open plantations. Comparison, based on discriminant analysis, of the habitat characteristics of forest plantations occupied and unoccupied by Nightjars suggests two things. First, that birds are more likely to occupy larger rather than smaller clearings and, second, that the study populations are close to their maxima. However, with continuing rotational felling, the area should continue to support a similar population.     

Indirect organogenesis from leaf explants of Hemidesmus indicus (L.) R. Br.: an important medicinal plant

Hemidesmus indicus (Asclepiadaceae) leaf explants were utilized for establishing culture in MS medium fortified with individual cytokinins, auxins, and their combinations. Optimum response (80%) was observed in N⁶-benzyladenine (BA, 20 μM) + indole-3-acetic acid (IAA, 1 μM) with 19.67 ± 0.81 shoots per explant. Roots were induced in ¼MS + indole-3-butyric acid (IBA, 20 μM).     

Chemical classification of cattle. 2. Phylogenetic tree and specific status of the Zebu

Phylogenetic trees for the ten major breed groups of cattle were constructed by Farris's (1972) maximum parsimony method, or Fitch & Margoliash's (1967) method, which averages ou the deviation over the entire assemblage. Both techniques yield essentially identical trees. The phylogenetic tree for the ten major cattle breed groups can be superimposed on a map of Europe and western Asia, the root of the tree being close to the 'fertile crescent' in Asia Minor, believed to be a primary centre of bovine domestication.
For some but not all protein variants there is a cline of gene frequencies as one proceeds from the British Isles and northwest Europe towards southeast Europe and Asia Minor, with the most extreme gene frequencies in the Zebu breeds of India. It is not clear to what extent the observed clines are primary or secondary, i.e., consequent to the initial migrations of cattle towards the end of the Pleistocene or consequent to the many migrations of man with his domesticated cattle. Such clines as exist are not in themselves sufficient to prove either selection versus genetic drift or to establish taxonomic ranking. Contrary to some suggestions in the literature, the biochemical evidence supports Linnaeus's original conclusions: Bos taurus and Bos indicus are distinct species.