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1.
This study was undertaken to provide cytogenetic information about onset and sequence of RBA-band replication on the inactive X-chromosomes of cattle, river buffalo and goat. Blood cultures were synchronized overnight with thymidine after 48 hours of growth. The cell block was released with fresh medium and the cells allowed to grow in the presence of BrdU and H33258 for 1, 2, 4, 6, 8, 10, 12 and 14 hours, including 20 minutes colcemide. Results show that: (a) the onset of RBA-banding replication was 12 hours before mitosis in cattle and river buffalo, 14 hours in the goat; (b) the replication process was still on in cattle and river buffalo one hour before mitosis, whereas it was off in the goat; consequently the length of the G2 phase was less than one hour in cattle and river buffalo and one hour or slightly longer in the goat; (c) the first band undergoing replication was identified as band Xq31 in cattle, homologous to band Xq34-36 in river buffalo and Xq24 in the goat; (d) the second replicating band was the Xp22 in cattle, homologous to band Xq21 in river buffalo and Xq34 in the goat, respectively; (e) the sequence of RBA-band replication was quite similar between cattle and river buffalo, but reversed in the goat, due to the wide chromosomal rearrangements which differentiated the X-chromosome of Caprinae from that of Bovinae.  相似文献   

2.
A G- and R-banding comparison of cattle (Bos taurus, 2n=60), goat (Capra hircus, 2n=60) and sheep (Ovis aries, 2n=54) chromosomes at the 450 band level was made. The study revealed a large number of banding homologies among the autosomes of the three species and resolved some ambiguities in arranging some of their small disputed acrocentrics by direct and indirect comparisons with some bovid marker chromosomes. A loss of the subcentromeric G-positive band in sheep chromosome 2q was observed when the G-banding patterns of sheep 2q and homologous cattle and goat chromosome 2 were compared. The chromosomal divergences among cattle, goat and river buffalo (Bubalus bubalis, 2n=50) sex chromosomes are shown to have occurred by pericentric and paracentric inversions with a loss (or acquisition) of constitutive heterochromatin.  相似文献   

3.
R-banded chromosomes of Vietnamese sika (VS) deer (Cervus nippon pseudaxis, 2N = 66), a threatened subspecies of sika deer endemic to Vietnam, are presented for the first time and were compared with bovine R-banded chromosomes to define a standard karyotype. Nineteen VS deer autosomes (CNP) were identified on the basis of the banding pattern relative to bovine chromosomes (BTA), while hypotheses for the remaining thirteen were proposed from comparisons with the published deer genetic map, BTA 1, 2, 5, 6, 8 and 9 each equivalent to two separate acrocentric CNP chromosomes and BTA 26 and 28 associated in a tandem fusion. To confirm these hypotheses, probes for the twenty-nine Texas nomenclature type I markers specific for each cattle autosome, sixteen other type I and fourteen microsatellite markers were used in FISH experiments on VS deer chromosomes. CNP7 presented the most complex rearrangement as compared with cattle chromosomes. A complete correspondence between VS deer and cattle chromosomes was established and it was extended with a comparison with the human karyotype to transfer human map information to this species of scientific and economic interest. Moreover, this work anchors the deer genetic linkage map to chromosome-specific markers. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

4.
Ohne ZusammenfassungMit 32 Textabbildungen und 1 Tabelle.  相似文献   

5.
In cattle, the repertoire of TCRBV genes that encode the variable region of T-cell receptor β-chains has not been fully characterized. In this study, cattle TCRBV genes were amplified from mRNA by anchored polymerase chain reaction and sequenced. Eleven new TCRBV gene sequences were found, and classified into seven subfamilies distinct from those previously identified.  相似文献   

6.
In cattle, the repertoire of TCRBV genes that encode the variable region of T-cell receptor beta-chains has not been fully characterized. In this study, cattle TCRBV genes were amplified from mRNA by anchored polymerase chain reaction and sequenced. Eleven new TCRBV gene sequences were found, and classified into seven subfamilies distinct from those previously identified.  相似文献   

7.
The study contains a comprehensive review of the literature on the brain of the cattle, followed by notes on form and location of the brain in the skull of the cow and of the diencephalon. In addition we point to some possibilities for locating the brain by stereotaxic manipulations. Several structural particularities are discussed, where to a limited extent references to structures of the brains of other domestic artiodactyla are made.  相似文献   

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Investigations were carried out on some statistical correlations between data measured (diameter and length of various ceca) and the age of the fetuses (n = 40). In addition, the volumes of the ceca were calculated at different stages of intrauterine development.  相似文献   

10.
11.
1. A histological examination of adipose tissue from 1- and 6-day-old calves showed a structure typical of white adipose tissue and no evidence of brown adipose tissue.2. Infusion of noradrenaline (1.0 mug/kg.min I.V.) into 1-to 6-day-old calves affected heart rate and respiratory rate but did not increase heat production, rectal temperature, skin temperature or skin evaporative loss.3. Cold exposure led to shivering and an increased oxygen consumption in the 6-day-old calf.4. Blood samples taken from 6-day-old calves in the cold (-1 degrees C) appeared to have a higher proportion of unesterified fatty acids in the total blood lipid than samples taken in an environment of 20 degrees C, but no change in fatty acid composition was found.5. It has been concluded that there is no non-shivering thermogenesis in the young calf.  相似文献   

12.
In the epithelium of the fetal bovine large intestine there are endocrine cells, predominantly at the base of the crypts. According to morphological characteristics, EC-cells and L-cells can be readily distinguished.  相似文献   

13.
Although the order of entry to a handling chute is related to social rank, it is still not clear what the consequences are for Zebu cattle of occupying different ranks when being exposed repeatedly to a stressful handling procedure. Eighteen Brahman cows were observed for 243 h to obtain information on social interactions. From that information, indices of success in displacing other individuals of the herd were calculated to reflect social status of each cow. One week after behavioral observations, the cows were forced 19 times to enter a handling chute where they were palpated and 7 ml of blood was collected from their caudal vein. To have an adrenal activity profile along the experimental period, five blood samples (Days 2, 6, 10, 15, and 19) were chosen for cortisol determination. On each sampling day, the average time in the chute, the order of entry, and a value of entrance consistency were calculated. On average, the high-ranking cows entered the chute before the medium- and low-ranking cows. Medium-ranking cows showed higher consistency when entering the race than high- and low-ranking cows. Low-ranking cows had significantly lower cortisol levels than the other two groups since the second sample (Day 6 in the race), and had higher cortisol levels the first time handled than at subsequent sampling days. It is suggested that low-ranking cows adopt a passive strategy that allows them to have a better control over the stressful event, while high-ranking cows respond with higher cortisol levels perhaps because of the need to become aroused to deal with challenges. It was concluded that the herd (a) habituated to repeat handling in a squeeze chute and (b) low-ranking cows responded with lower cortisol concentration to handling.  相似文献   

14.
对54例异常核型者和30名对照作紫外线诱导姊妹染色单体交换及低叶酸诱导染色体脆性部位表达和微核检测,发现异常核型者三项实验数值限(8.75±2.14/细胞、3.89±1.18%、7.30±1.98%)比对照(6.13±1.03/细胞、2.03±0.72%、4.50±1.11%)有极显著性增加,提示在不良环境因素中,异常核型者更易发生染色体畸变。  相似文献   

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The parenchyma cells of the pineal organ from 20 cattle (10 week-old female calfs, from one year to several years of age female and male cattle) and 14 pigs (8- to 9-month-old female pigs) were investigated with histochemical methods. Carbohydrates are evident in a insignificant quantity. The content of lipids is very high, according to the age the quantity varying. Proteins are evident, but only in small quantities. The content of ribonucleic acid is very high.  相似文献   

18.
Summary The study describes the variations in distribution and cross-sectional area (fibre size) of three muscle fibre types (I, IIA, IIB) in 34 of the largest muscles of the bull (Bos taurus). The animals had been kept strictly unexercised for one year before slaughter. Representative sampling was done at 15 positions within each muscle, and from 2700 to 4500 fibres were analysed in each muscle. Different intermuscular patterns are described. The overall volume fraction (%) of type I fibres was about 10% higher in the forepart muscles than in the hindpart muscles (41% and 31%, respectively), while the mean content of type IIB fibres was similar. Type I fibres were particularly abundant in antigravity muscles. Of these, the hindlimb muscles contained 50% more type I fibres (by weight) than those of the forelimb. Typical antigravity antagonists contained very few type I fibres. In the thigh cross-section the proportion of type I fibres was highest in the anterior and medial parts, while the IIB fibres tended to be concentrated in the superficial and posterior parts. Intramuscular patterns were revealed, with type I fibres becoming gradually more abundant from superficial to deep regions, while IIB fibres had an opposite distribution. This was particularly evident in the thigh proper and in the scapular region. Within each fasciculus of all the muscles, the I fibres in the muscles of the forepart were on average about 15% larger than those of the muscles in the hindpart. The IIB fibres were on average about 10% larger in the hindpart than in the forepart muscles. A covariation between the proportion of type I and IIB fibres and their cross-sectional area was indicated.  相似文献   

19.
Cross infections were carried out by dosing parasite-free calves and lambs with third stage nematode larvae cultured from the faeces of reindeer and elk. Two lambs each received 20,000 larvae from reindeer, and one lamb 20,000 larvae from elk. One calf received 50,000 larvae from reindeer and one 50,000 from elk. The animals were killed 28 days after infection. Egg output did not differ significantly between the lambs nor between the calves, but in the lambs the output was much higher than in the calves (highest cound 4300 versus 275). Worm counts varied among the animals independent of the origin of the larvae. The highest take was found in the lamb infected with larvae from elk (81.5%) and the lowest in the calf infected with larvae from elk (15.1%).Ostertagia leptospicularis was the dominant species (80% or more) and the only other species present wereSkrjabinagia kolchida andSpiculopteragia boehmi. The latter was found in a higher percentage (14.0 and 10.4) in the animals that received larvae cultured from elk faeces. Under natural conditionsO. leptospicularis is possibly the only pathogenic species that can play a role in cross contamination to cattle and sheep.  相似文献   

20.
The objective of the study was to investigate the light and ultrastructural morphology of dominant and subordinate oocytes from zebu (Bos indicus) cattle. Healthy cycling animals, which had a well-developed corpus luteum as judged by rectal palpation, were administered cloprostenol to induce luteolysis and therefore ovulation. The animals were slaughtered at days 3–11 post-ovulation, but those slaughtered at days 8–11 received a second injection of cloprostenol at day 7. Cumulus-oocyte complexes were aspirated from the largest (dominant) and the second largest (subordinate) follicles, and processed for transmission electron microscopy. Up to day 7, the dominant oocyte presented a peripherally located spherical oocyte nucleus with a compact dense fibrillar nucleolus. After day 7, the nuclear envelope became undulated and the nucleolus vacuolated. The nuclei contained an average of four nucleoli. In addition to vesicles, mitochondria, smooth endoplasmic reticulum, Golgi complexes and cortical granules, the ooplasm contained annulate lamellae and microtubules. Moreover, mitochondrial granules and pleomorphic forms of mitochondria were commonly observed. Some subordinate oocytes exhibited advanced stages of meiotic maturation. It is concluded that (1) the dominant oocyte undergoes certain prematurational changes, including nucleolus vacuolation, in the period from luteolysis up to the presumptive occurrence of the LH peak and (2) subordinate oocytes may undergo meiotic maturation.  相似文献   

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