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2.
Jane J. Turner James G. Herndon Maria-Carmen Ruiz de Elvira Delwood C. Collins 《Primates; journal of primatology》1989,30(4):523-529
Endogenous testosterone levels were measured in association with sexual, aggressive, and social/affiliative behaviors in 11
outdoor-housed female rhesus monkeys over a ten-month period. Several behaviors (sex directed toward the male, sex received
from the male, aggression directed toward the male, submission directed toward the male, submission directed toward the female,
and groom another female) were significantly (p<0.05) positively correlated with testosterone in from one to five females. No trends were strong enough across all females
to suggest that any of these correlations have species-wide significance. Factor analysis revealed clearcut clusters of behaviors,
but elevations in testosterone were not strongly associated with any of these clusters. It is concluded that endogenous testosterone
levels have little measurable effect on overt behavior in female rhesus monkeys. 相似文献
4.
Summary Female gametangia of the normal bisexual Allomyces species are richer in fluorescently probed (FITC) actin, independent of their apical or subapical positioning during differentiation on the fertile hyphae. The anti-actin, cytochalasin D, can selectively suppress male differentiation in both species. 相似文献
5.
Dramatic founder effects in Amerindian mitochondrial DNAs 总被引:33,自引:0,他引:33
Southwestern American Indian (Amerindian) mitochondrial DNAs (mtDNAs) were analyzed with restriction endonucleases and found to contain Asian restriction fragment length polymorphisms (RFLPs) but at frequencies very different from those found in Asia. One rare Asian HincII RFLP was found in 40% of the Amerindians. Several mtDNAs were discovered which have not yet been observed on other continents and different tribes were found to have distinctive mtDNAs. Since the mtDNA is inherited exclusively through the maternal lineage, these results suggest that Amerindian tribes were founded by small numbers of female lineages and that new mutations have been fixed in these lineages since their separation from Asia. 相似文献
6.
A stranger mother-son pair of the chimpanzee was observed twice interacting with conspecifics of a neighbouring unit-group:
first, when the mother and son accidentally encountered them within the core area of the former; second, when the mother and
son temporarily immigrated for about one week. On both occasions, the mother and son were severely attacked by adult males
of the neighbouring unit-group, and would have been killed had it not been for human intervention. The main target of the
aggression was not the infant, but the mother. Some adult males intervened and prevented other males and females from attacking
the mother-son pair. Moreover, most adult males displayed an ambivalent attitude since they showed aggression towards them
on one occasion, but groomed, reassured and played on another. The reasons for the variable responses of adult males to a
stranger female are discussed in terms of possible differences in their mating strategies. 相似文献
7.
8.
To evaluate whether the median eminence (ME) is a site of action of CRF (corticotropin releasing factor) on GH secretion and
to determine the possible role of estradiol and progesterone in modifying theses secretion, we injected CRF (0.25, 0.75, 1,
and 1.5 nmol of peptide dissolved in 1 μl of water) directly into the ME in three experimental groups of rats: Long-term ovariectomized
(OVX); OVX primed by estradiol (OVX±E) and OVX primed by estradiol plus progesterone (OVX±EP). Blood was collected to determine
GH (30, 60, 90, and 120 min postinjection) Serum T3, T4, and glucose levels were measured in OVX±E rats 30 min postinjection. CRF at all doses studied significantly decreased serum
GH levels in the three experimental groups. Serum T3, T4, and glucose levels were unchanged after CRF administration. The results suggest that: CRF inhibits “per se” GH secretion,
at least in part, by a central action in the ME. The inhibitory effect of CRF on GH is independent of the estrogen/progesterone
status of the animal. CRF at ME levels may participate in a variety of stress-related responses, including growth inhibition,
through GH suppression. 相似文献
9.
东方次睾吸虫电镜研究(吸虫纲:后睾科)V.雌性生殖器官 总被引:1,自引:0,他引:1
东方次睾吸虫雌性生殖器官(卵巢、输卵管、卵黄-输卵管、卵模、梅氏腺和子宫)透射电镜 观察。卵巢内有不同成熟期的生殖细胞,成熟初级卵母细胞有几个靠近核的核仁样小聚体和许多沿 质膜的皮质颗粒。首次发现并描述卵巢和输卵管接合处(卵巢壶腹)的超微结构。输卵管上皮为纤 毛状。梅氏腺仅一种类型膜状小体细胞,经有微管支持的细小管道穿过卵模将膜状小体排入卵模腔 内。在卵黄-输卵管和卵模中有精子,卵模和子宫中有受精卵、虫卵(扫描电镜):大小 26. 05× 11.46-13.55μm,卵盖直径6.26-6. 89μp,卵壳表面布满膜状隆起。文中对卵巢和梅氏腺的超微 结构特点进行了讨论。 相似文献
10.
In nonparthenocarpic cucumber, analysis of the interaction between season and female receptivity demonstrated two different modes of fruit development and seed set. Spring climatic conditions induced significantly longer ovaries at anthesis with an autonomous fruit set as in natural parthenocarpy. Autumn climatic conditions induced smaller ovaries with fruit set influenced by the pollination stage of the female flower. These differences involve, during fruit development, a regulation of the empty seed number especially at both ends of female receptivity period. Indeed, seasons have no effect on ovule receptivity and fertility measured by full seed number. It is supposed that priority is given to seeds with an embryo in the competition for limited maternal resources in spring as well as in autumn. In spring, the use of irradiated pollen during the whole female receptivity period did not modify the seed set profile. Moreover, a cytological study of 6-day-old ovules pollinated by irradiated pollen has revealed a similar precocious embryogenesis compared to the control. In cucumber, pollination with irradiated pollen involves stenospermocarpy rather than induced parthenocarpy. However, we have not been able to determine whether the early abortive embryogenesis induced by irradiated pollen is gynogenetic or abnormal zygotic. 相似文献