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231.
We have investigated the reproductive development of the tropically adapted Santa Inês ram, the most common hair sheep in Brazil. From 8 to 48 weeks of age, 16 animals were evaluated for body and testis growth, semen parameters, testosterone concentrations and seminal plasma proteins, using two‐dimensional SDS‐PAGE. Animals were weaned at 30 days and kept in feedlots thereafter, receiving hay, concentrate (18% of crude protein) and mineral supplement. Body weight increased from 12.3 ± 0.7 to 54.3 ± 1.6 kg between 8 and 48 weeks (p < 0.05), but changes in thoracic perimeter and scrotal circumference were non‐significant after 36 weeks (p > 0.05). The percentage of motile sperm increased slowly until 23 weeks and more rapidly after that age, but significant changes in progressive motility occurred after 25 weeks. Presence of abnormal sperm related inversely to age. Most significant changes in sperm concentration occurred between 38 and 44 weeks (0.38 ± 0.05 to 1.14 ± 0.24 × 109 cells/ml, p < 0.05) and testosterone reached its highest concentrations at 42 weeks, decreasing afterwards. Rams reached puberty at 28.2 ± 0.8 weeks. The number of protein spots on seminal plasma gels was similar from 15 to 18 weeks (45 and 47 spots; p > 0.05), increased until 24 weeks (141 spots) and 28 weeks (170 spots; p < 0.05) and remained without significant (p > 0.05) changes from 28 to 48 weeks (186 ± 10 spots). Furthermore, the intensity of selected spots on 2D maps increased (p < 0.05) between 15 and 28 weeks, which preceded or coincided with the main developmental changes in sperm motility and percentage of defective sperm in the ejaculates. These results will support future studies designed to characterize specific seminal plasma proteins whose expression relate to the development of testis, epididymis and accessory sex glands.  相似文献   
232.
Manipulation of flowering time to develop cultivars with desired maturity dates is fundamental in plant breeding.It is desirable to generate polyploid rapeseed(Brassica napus L.)germplasm with varying flowering time controlled by a few genes.In the present study,Bna SVP,a rapeseed homolog of the Arabidopsis SVP(Short Vegetative Phase)gene,was characterized and a set of mutants was developed using a CRISPR/Cas9-based gene-editing tool.A single construct targeting multiple sites was successfully applied to precisely mutate four copies of Bna SVP.The induced mutations in these copies were stably transmitted to subsequent generations.Homozygous mutants with loss-of-function alleles and free transgenic elements were generated across the four Bna SVP homologs.All mutant T1lines tested in two environments(summer and winter growing seasons)showed early-flowering phenotypes.The decrease in flowering time was correlated with the number of mutated Bna SVP alleles.The quadruple mutants showed the shortest flowering time,with a mean decrease of 40.6%–50.7%in length relative to the wild type under the two growth conditions.Our study demonstrates the quantitative involvement of Bna SVP copies in the regulation of flowering time and provides valuable resources for rapeseed breeding.  相似文献   
233.
Fucoidans constitute a large family of sulfated polysaccharides with several biochemical properties. A commercial fucoidan from brown algae, containing low molecular weight polysaccharidic species constituted of l-fucose, uronic acids and sulfate groups, was simply treated here with calcium acetate solution. This treatment led to a purified fraction with a yield of 45%. The physicochemical characterizations of the purified fucoidan using colorimetric assay, MALLS, dRI, FT-IR, NMR, exhibited molecular weight distributions and chemical profiles similar for both fucoidans whereas the sulfate and l-fucose contents increased by 16% and 71%, respectively. The biodistribution study in rat of both compounds labeled with 99mTc evidenced a predominant renal elimination of the purified fucoidan, but the crude fucoidan was mainly retained in liver and spleen. In rat myocardial ischemia-reperfusion, we then demonstrated the better efficiency of the purified fucoidan. This purified sulfated polysaccharide appears promising for the development of molecular imaging in acute coronary syndrome.  相似文献   
234.
The aim of this study was to examine effects of an antibiotic combination at different concentrations on growth of mycoplasma and ureaplasma during cooled storage of canine semen (n = 20). Semen aliquots were diluted with Tris–citric acid–fructose–egg yolk extender containing either 1.0 g/l streptomycin and 0.6 g/l benzylpenicillin (control) or a combination of gentamycin, tylosin, lincomycin and spectinomycin (GTLS‐1: 0.25, 0.05, 0.15 and 0.3; GTLS‐2: 0.5, 0.1, 0.3 and 0.6; GTLS‐3: 1.0, 0.2, 0.6 and 1.2 g/l). Samples were assessed for motility and membrane integrity by computer‐assisted sperm analysis immediately after dilution and at 24, 48 and 72 h of cooled storage. Morphologically, normal spermatozoa were determined, and bacterial culture was performed at 24 and 72 h. Mycoplasma spp. were detected in 14 of 20 ejaculates (70%) with severe growth in 12 samples. A reduction but not total elimination of mycoplasma growth occurred in all GTLS extenders with the most pronounced reduction in group GTLS‐3 (control vs GTLS‐1 and GTLS‐2 p < 0.05, control vs GTLS‐3 p < 0.001). Ureaplasmas were detected in four ejaculates, and growth was reduced to the same extent in GTLS and control extender. Progressive motility in all groups, total motility in groups GTLS 1–3 and percentage of membrane‐intact spermatozoa in groups GTLS 2 and 3 decreased slightly (p < 0.05) over time. In conclusion, dilution of canine semen with GTLS extender has no major detrimental effects on spermatozoa during cooled storage. It reduced the growth but did not totally eliminate mycoplasmas and ureaplasmas from cooled‐stored dog semen.  相似文献   
235.
The aim of this study was to evaluate the reproductive performance of gilts that had a similar age but different weights at the onset of puberty stimulation by boar exposure at 144 days. Gilts were divided into two groups according to their lifetime growth rate from birth to approximately 144 days of age. Mean growth rates at this moment were 577 and 724 g/day for group 1 (G1; n = 58) and group 2 (G2; n = 58), respectively. After selection, gilts were weighed at approximately 155, 165 and 175 days of age, on the insemination day and at slaughter. Gilts were inseminated, on average, at 193 days of age and were slaughtered 32 days after insemination, when the number of corpora lutea and embryos were recorded. Higher growth rate gilts (G2) reached puberty earlier (155.3 vs 164.1 days; p < 0.01). More gilts of G2 group attained puberty by 190 days of age (p = 0.004) than G1 gilts (95%; 55/58 vs 76%; 44/58). The anoestrous rate, until 60 days after the onset of boar exposure was higher (p < 0.01) in G1 (19.0%; 11/58) than in G2 (3.4%; 2/58) group. However, there were no differences in the pregnancy rate (90.7 vs 94.5), ovulation rate (15.9 vs 16.5), total embryos (12.9 vs 11.7), viable embryos (12.0 vs 11.1) and embryo survival (73.7% vs 68.5%), between G1 gilts and G2 gilts, respectively (p > 0.05). High growth rate gilts attain puberty earlier and have a lower anoestrous rate than low growth rate gilts.  相似文献   
236.
Normal mammalian sex differentiation takes place in three genetically controlled steps: chromosomal sex determination (XX or XY), gonadal differentiation and development of the phenotypic sex. Animals are considered to be sex reversed if chromosomal sex determination and gonadal development are not in agreement. In this report, sex reversal is described in a 1.5-year-old Podenco dog that was referred because of suspected recurrent growth of a previously removed os clitoridis in the vulva. With that exception the dog was phenotypically female, but had never been in oestrus and exhibited male behaviour. Abdominal ultrasonography showed a small tubular structure dorsal to the bladder, consistent with a uterus. An ovoid structure resembling a gonad was visible between the right kidney and inguinal canal. Plasma testosterone concentrations before and after GnRH administration indicated the presence of functional testicular tissue. Two testes, each with its epididymis and ductus deferens, and a complete bicornuate uterus were removed surgically. Cytogenetic analysis of peripheral blood lymphocytes showed a normal female karyotype (78, XX). These findings are consistent with the diagnosis of an XX male. PCR analysis of genomic DNA revealed that the SRY gene was absent. In summary, this report describes the first SRY-negative XX male Podenco dog with an almost complete female phenotype despite high basal and stimulated plasma testosterone concentrations. It is hypothesized that the clinical observations in this dog may have been caused by reduced and delayed Müllerian-inhibiting substance secretion and the absence of conversion of testosterone to dihydrotestosterone due to 5α-reductase deficiency.  相似文献   
237.
Fourteen genetically diverse inbred lines comprising of four genic male sterile lines and 10 often pollinated lines as testers were crossed following ‘line × tester’ mating design to generate 40 F1s. These F1s, parents and check ‘CH-27’ were evaluated in α-lattice square design, replicated thrice during summer seasons of 2020 and 2021. The male sterile line DPChMS 9-2 was good general combiner for marketable fruit yield and eight other component traits while testers namely, DPCh 10, PBC 535, VVG, Him Palam Mirch-2 and DPCh 40 showed significant GCA for majority of yield related traits. The hybrids DPChMS 9-2 × HPM-2, DPChMS 9-2 × DPCh 40, DPChMS 9-2 × DPCh 101, DPChMS 9-2× VVG and DPChMS 26-1× HPM-1 were the most desirable based on specific combining ability (SCA) and economic heterosis for fruit yield and other important traits. Heterosis was positively correlated with SCA indicating prediction of potential hybrids can be made based on both these parameters simultaneously. Present study provides an opportunity to exploit top hybrids for stability and commercial cultivation.  相似文献   
238.
The ammonia flux from a green manured field was measured at a site in southern Italy. The green manure was provided by ploughing in about 66 and 78 t ha−1 of broad beans at the flowering stage during the spring in 1995 and 1996. The NH3 flux was estimated by means of the micrometeorological simplified aerodynamic method with the ammonia concentration measured at two levels above soil surface. Ammonia concentration was measured over a 2–3 h sampling period by trapping air NH3 in a H2SO4 solution and analysing this sample in the laboratory with the colorimetric method using the Nessler solution. About 70% of the total amount of ammonia was emitted in the first two days immediately after manuring. The NH3 flux was regulated by the same mechanism as the water vapour transport. Seventy percent of the daily ammonia was emitted around noon. The ammonia emission stopped during rainy and cold days and started again as soon as solar radiation, soil and air temperature increased, following plant decomposition. The total amount of ammonia emitted in the experimental period (28 days in 1995 and 18 days in 1996) was about 13 kg ha−1 for both years.  相似文献   
239.
Chemosensory proteins (CSPs) are important molecular components of the insect olfactory system, which are involved in capturing, binding, and transporting hydrophobic odour molecules across the sensillum in sensillar lymph in regulating insect behavior. This protein family (CSPs) is also involved in many other systems that are not linked to olfactory receptors in olfactory sensilla. The brown planthopper (BPH) is a monophagous pest of rice that causes damage by sucking phloem sap and transmitting a number of diseases caused by viruses. In this study, fluorescence competitive binding assay and fluorescence quenching assay at acidic pH were performed as well as homology modelling to describe the binding affinity of NlugCSP10. Fluorescence competitive binding assay (FCBA) demonstrated that NlugCSP10 bound strongly to nonadecane, farnesene, and 2-tridecanone at acidic pH. The results of FCBA indicated that NlugCSP10 bound different ligands at the physiological pH (5.0) of the bulk sensillum lymph. Fluorescence quenching assay demonstrated that NlugCSP10 generated a stable complex with 2-tridecanone, while two ligands nonadecane and farnesene collided due to molecular collisions. The interaction of selected ligands with the modelled structure of NlugCSP10 was also analyzed, which found the key amino acids (Gln23, Gln24, Gln25, Asn27, Met33, Ser34, Ile35, Tyr36, Asn42, Met43, Val45, Asn46, Asn93, Arg96, Ala97, Lys99, and Ala100) in NlugCSP10 that were involved in binding of volatile compounds. The present study contributes to the binding profile of NlugCSP10 that promotes the development of behaviorally active ligands based on BPH olfactory system.  相似文献   
240.
Agricultural water markets can facilitate adjustments to water scarcity and competition and enhance economic efficiency, but markets cannot automatically balance efficiency, equity and environmental sustainability goals. The consequences of water trading on soil salinity in irrigation areas are not yet fully understood, but recognized as an issue that needs to be analysed. This paper explores the nexus between water trading and groundwater-induced soil salinity in a selected irrigated area in the Murray-Darling Basin. Results show that minimum irrigation intensities must be met to flush salts out of the root zone especially in shallow water table/high salinity impact areas. Such minimum irrigation intensities are helpful but not necessarily in deep water table/low salinity impact areas. Should water markets lead to permanent water transfers out of mature irrigation areas, minimum irrigation intensity needs might not be met in high salinity impact areas, causing substantial negative impacts on resource quality and agricultural productivity. Water trading that adds to salinity cannot be economically viable in the long run. The tradeoffs between water trading and environmental and equity goals need to be determined. This work contributes to the wider debate on Australian water policy aimed at achieving water security through water trading in the Murray-Darling Basin.  相似文献   
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