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31.
In order to determine if PGF(2)alpha could improve fertility in repeat breeder females when added to semen used for artificial insemination (AI) the following trial was performed. In a large indoor Hungarian production unit of 2000 sows, 667 repeat breeding females were assigned to two groups and were treated as follows: Group 1 (n=322), received PGF(2)alpha, added to the semen immediately before AI; Group 2 (n=345), received AI with untreated semen. Conception rate, farrowing rate, subsequent total and live born litter size and subsequent weaning to estrus intervals were evaluated. Conception and farrowing rates revealed highly significant differences between the PGF(2)alpha-treated and nontreated animals (P<0.001). Subsequent total born (P<0.07), and live born litter size (P<0.13), and subsequent weaning to estrus intervals (P<0.23) showed no significant differences. It is reasonable to suggest that exogenous PGF(2)alpha added to AI semen improves conception and farrowing rates. 相似文献
32.
Nedeljkovic N Djordjevic V Horvat A Nikezic G Kanazir DT 《Physiological research / Academia Scientiarum Bohemoslovaca》2000,49(4):419-426
Abundant evidence indicates that ATP and adenosine act as neurotransmitters or co-transmitters, influencing nerve cell physiology in various ways. Therefore, regulation of ATP-metabolizing enzymes is essential for the normal development and function of neuronal tissue. In the present study we have examined the effect of gonadal (OVX) or adrenal (ADX) steroid hormone deprivation on the activity and expression of synaptic membrane ecto-ATPase in three extrahypothalamic brain areas of female rats, primarily not associated with reproductive function. It was shown that OVX significantly increased ecto-ATPase activity and the relative abundance of this enzyme in the hippocampal (Hip) and caudate nucleus (CN), but not in brain stem (BS) membrane preparations. ADX was followed by an upregulation of the enzyme activity and its relative abundance in all the brain areas investigated. The highest enzyme activity and the most profound effects of OVX and ADX were detected in the CN. The results obtained indicate that ADX and OVX upregulate the expression of ecto-ATPase, potentiating the production of adenosine in synaptic cleft thus modulating the activity of numerous neurotransmitter systems in distinct areas of the CNS. 相似文献
33.
Streptomyces species have a linear chromosome of approximately 8 Mb in size. Many strains also carry linear plasmids. Most of these linear elements contain terminal proteins covalently bound to the 5 ends of the DNA. Using a method for the visualisation of terminal DNA fragments in agarose gels, it was possible to see three fragments in S. rimosus and five fragments in S. avermitilis. The method was also used to clone the 298 bp BamHI fragment carrying the left end of plasmid SLP2. Analysis of the sequence showed that the end resembled other Streptomyces chromosome and plasmid ends, but there were eight palindromes (instead of seven) and a tandem duplication of a 14 bp sequence. 相似文献
34.
Predrag Slijepcevic 《Chromosoma》1998,107(2):136-140
The Robertsonian (Rb) fusion, a chromosome rearrangement involving centric fusion of two acro-(telo)centric chromosomes to
form a single metacentric, is one of the most frequent events in mammalian karyotype evolution. Since one of the functions
of telomeres is to preserve chromosome integrity, a prerequisite for the formation of Rb fusions should be either telomere
loss or telomere inactivation. Possible mechanisms underlying the formation of various types of Rb fusion are discussed here.
For example, Rb fusion in wild mice involves complete loss of p-arm telomeres by chromosome breakage within minor satellite
sequences. By contrast, interstitial telomeric sites are found in the pericentromeric regions of chromosomes originating from
a number of vertebrate species, suggesting the occurrence of Rb-like fusion without loss of telomeres, a possibility consistent
with some form of telomere inactivation. Finally, a recent study suggests that telomere shortening induced by the deletion
of the telomerase RNA gene in the mouse germ-line leads to telomere loss and high frequencies of Rb fusion in mouse somatic
cells. Thus, at least three mechanisms in mammalian cells lead to the formation of Rb fusions.
Received: 11 November 1997 / Accepted: 21 December 1997 相似文献
35.
Jasnic N Korac A Velickovic K Golic I Djordjevic J Djurasevic S Djordjevic I Vujovic P Cvijic G 《Folia histochemica et cytobiologica / Polish Academy of Sciences, Polish Histochemical and Cytochemical Society》2010,48(4):507-512
The increased ambient temperature affects the function of hypothalamic-pituitary-adrenal (HPA) axis. Since the correlation among vasopressin (VP), adrenocorticotropic hormone (ACTH) and corticosterone (CORT) responses to various stressors have been long recognized, the aim of this study was to reveal the aforementioned hormones production and morphology of the pituitary gland after exposure to acute heat. Rats were exposed to high ambient temperature (38 °C) for 20 or 60 minutes. The circulating hormones were determined by an ELISA test or chemiluminescence's method. The results obtained show the elevation in ACTH and CORT secretion depending on the duration of heat exposure. The VP concentration increased only after prolonged exposure to heat (60 min). The pituitary morphology was examined by routine and fluorescent immunohistochemistry as well as electron microscopy. Observed changes in the anterior and posterior pituitary well corresponded to circulating hormones, regarding the volume density of ACTH-immunopositive cells, percentage of ACTH immunopositive area v. total area and number of VP-immunopositive containing varicose fibers per total area. Acute heat exposure also induced changes in shapes of ACTH-immunopositive cells. Cells appeared stellate with numerous slender cytoplasmic processes and degranulated, which is the most obvious after 20 min. In addition, immunopositivity of endothelial and anterior pituitary cells for VP suggests its influence on ACTH secretion. 相似文献
36.
We previously identified a Chr 15 quantitative trait locus (QTL) Fob3b in lines of mice selected for high (Fat line) and low (Lean line) body fat content that represent a unique model of polygenic obesity. Here we genetically dissected the Fob3b interval by analyzing the phenotypes of eight overlapping congenic lines and four F2 congenic intercrosses and prioritized candidates by bioinformatics approaches. Analyses revealed that the Fob3b QTL consists of at least two separate linked QTLs Fob3b1 and Fob3b2. They exhibit additive inheritance and are linked in coupling with alleles originating from the Lean line, decreasing obesity-related traits. In further analyses, we focused on Fob3b1 because it had a larger effect on obesity-related traits than Fob3b2, e.g., the difference between homozygotes for adiposity index (ADI) percentage was 1.22 and 0.77% for Fob3b1 and Fob3b2, respectively. A set of bioinformatics tools was used to narrow down positional candidates from 85 to 4 high-priority Fob3b1 candidates. A previous single Fob3b QTL was therefore resolved into another two closely linked QTLs, confirming the fractal nature of QTLs mapped at low resolution. The interval of the original Fob3b QTL was narrowed from 22.39 to 4.98 Mbp for Fob3b1 and to 7.68 Mbp for Fob3b2, which excluded the previously assigned candidate squalene epoxidase (Sqle) as the causal gene because it maps proximal to refined Fob3b1 and Fob3b2 intervals. A high-resolution map along with prioritization of Fob3b1 candidates by bioinformatics represents an important step forward to final identification of the Chr 15 obesity QTL. 相似文献
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39.
Novosel N. Mišić Radić T. Levak Zorinc M. Zemla J. Lekka M. Vrana I. Gašparović B. Horvat L. Kasum D. Legović T. Žutinić P. Gligora Udovič M. Ivošević DeNardis N. 《Journal of applied phycology》2022,34(3):1293-1309
Journal of Applied Phycology - This study examines how salinity reduction triggers the response of three marine microalgae at the molecular and unicellular levels in terms of chemical, mechanical,... 相似文献
40.