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排序方式: 共有1093条查询结果,搜索用时 812 毫秒
1.
Paloma Rocha Arakaki Paula Andrea Borges Salgado Joo Diego de Agostini Losano Dbora Rodrigues Gonalves Rodrigo del Rio do Valle Ricardo Jos Garcia Pereira Marcilio Nichi 《American journal of primatology》2019,81(12)
Wild animal genetic resource banking (GRB) represents a valuable tool in conservation breeding programs, particularly in cases involving endangered species such as the golden‐headed lion tamarin (Leontopithecus chrysomelas). Thus, we aimed to assess a sperm freezing protocol for golden‐headed lion tamarins using two different exenders: BotuBOV® (BB) and Test Yolk Buffer® (TYB). Ejaculates were collected by penile vibrostimulation from animals housed at São Paulo Zoological Park Foundation, São Paulo, Brazil, and after immediate analysis, two aliquots were diluted in BB and TYB. Postthawing samples were evaluated for total and progressive motility, plasma membrane and acrosome integrities, mitochondrial activity, susceptibility to oxidative stress, and sperm–egg‐binding. No differences between BB and TYB were found for most seminal parameters, except for acrosome integrity and susceptibility to oxidative stress (in both cases BB showed higher values). However, in spite of these differences and regardless of the extender used, postthaw sperm motility and viability with the described protocol were encouraging (on average >50% and >80%, respectively), indicating that sperm cryopreservation may be a short‐term measure for the conservation of golden‐headed lion tamarins. 相似文献
2.
The allometric relationships between canine base area, first molar and summed molar crown area, and the glabella–opisthocranion distance, and the direct allometric relationships between canine and molar size have been established in five primate taxa. Separate sex and combined sex ‘intraspecific’, and ‘interspecific’ regression and ‘best fit’ allometry coefficients were computed. This analysis showed that for any increase in glabella–opisthocranion length, the rate of increase in canine size exceeds the rate of increase in molar area, and ‘best fit’ solutions indicate that canine base area is positively allometric when related directly to molar crown area. These results were compared with data available for the ‘gracile’ australopithecine, A. africanus, and two ‘robust’ australopithecine taxa, A. boisei and A. robustus. The differences in canine and molar size which occur between the ‘gracile’ taxon and the two ‘robust’ taxa do not correspond to any of the trends in the comparative allometric models. Data on glabella–opisthocranion length for the fossils, meagre though they are, show that while the proportional increase in molar crown area between the taxa corresponds to comparative allometry models, the reduced canine size in the ‘robust’ taxa is against comparative allometric trends. These results indicate that, at least in terms of canine/molar proportions, the differences between the ‘gracile’ and ‘robust’ australopithecines are not merely allometric and may indicate significant dietary or behavioural differences. 相似文献
3.
Glenn C. Conroy 《International journal of primatology》1987,8(2):115-137
Body-weight estimates of fossil primates are commonly used to infer many important aspects of primate paleobiology, including
diet, ecology, and relative encephalization. It is important to examine carefully the methodologies and problems associated
with such estimates and the degree to which one can have confidence in them. New regression equations for predicting body
weight in fossil primates are given which provide body-weight estimates for most nonhominid primate species in the fossil
record. The consequences of using different subgroups (evolutionary “grades”) of primate species to estimate fossil-primate
body weights are explored and the implications of these results for interpreting the primate fossil record are discussed.
All species (fossil and extant) were separated into the following “grades”: prosimian grade, monkey grade, ape grade, anthropoid
grade, and all-primates grade. Regression equations relating lower molar size to body weight for each of these grades were
then calculated. In addition, a female-anthropoid grade regression was also calculated for predicting body weight infernales
of extinct, sexually dimorphic anthropoid species. These equations were then used to generate the fossil-primate body weights.
In many instances, the predicted fossil-primate body weights differ substantially from previous estimates. 相似文献
4.
Robert S. Corruccini 《International journal of primatology》1987,8(2):99-114
Dental characteristics figure large in primate taxonomy because teeth fossilize commonly and reflect dietary adaptations.
The mammalian dentinoenamel junction (DEJ) plays a crucial role throughout odontogenesis in determining the ultimate crown
configuration, being the interface between the papilla and the dental cap. The final configuration of the dentin surface reflects
the epithelium more closely than does the enamel surface of the crown. Enamel deposition occurs relatively late in calcification,
often causing many changes from the pattern residing in the DEJ; the genetic determination of the two surfaces also differs.
Comparative study of the DEJ (and its differences from the enamel crown) is a potential adjunct to dentition-based taxonomy
and may help to resolve certain cusp homologies and morphogenetic order of appearance. Primate teeth were stripped of enamel
after measurement, mapping, and anatomical observations on the original crown. The dentin surfaces thus revealed differ from
the enamel surfaces in several respects and shed new light on such dental problem areas as the origin of the hypocone, the
affinities of lorisoids and callitrichids, the monophyly of the anthropoid grade, and human affinities. 相似文献
5.
Brian T. Shea 《International journal of primatology》1987,8(2):139-156
In order to understand fully the generally high level of encephalization observed in living primates, we must determine why
early primates exhibited moderately large relative brain sizes compared to their early Tertiary contemporaries. The relatively
high degree of encephalization in early primates may be related at least in part to the fact that they were highly unusualamong mammals in combining a small body size with a strongly precocial reporductive strategy. Other small, precocial mammals
also exhibit moderately high levels of encephalization; but primates appear to have been truly uniquein being the only such small-sized and highly precocial group to give rise to extensive radiations of larger descendants.
This is a key element in understanding primate brain evolution, because the initial “head start” of the early primates was
translated up to larger sizes in descendants. The possible relationships among encephalization, precociality, small size,
and arboreality are discussed, particularly in light of recent debates concerning the validity of the superorder Archonta.
This work emphasizes that we need to consider relative brain size as but one element in a complex synergistic network of morphological
and life-history features. 相似文献
6.
The present paper describes a simple technique that hardens the shell of nuts and makes the use of a tool to crack them open more compelling. Walnuts were coated with a dough of sawdust and nontoxic white glue in different combinations; they were tested for hardness by using machines normally used to test different kinds of wood. Data on relative hardness for uncoated walnuts and walnuts coated with dough of two different combinations are presented. The coated walnuts were significantly harder to break than the uncoated ones, whereas no significant difference was found when comparing the hardness of two types of coated walnuts. Furthermore, observations on a captive group of tufted capuchins (Cebus apella) are described. The monkeys needed significantly more time to break open the coated walnuts. Early results show that coated walnuts may favor acquistion of tool use skills in a juvenile capuchin. 相似文献
7.
In this study three different techniques suitable to recover high molecular weight genomic DNA from small blood samples of
different species of malagasy primates are compared: we suggest the use of a very simple phenol-chlorophorm DNA extraction
for badly stored or coagulated blood as for samples collected under difficult field conditions.
Furthermore we briefly describe the use of this DNA in determining RLFP patterns and DNA fingerprints. 相似文献
8.
Host defense deficiency in newborn nonhuman primate lungs 总被引:2,自引:0,他引:2
A T Cheung G Kurland M E Miller E W Ford S A Ayin E M Walsh 《Journal of medical primatology》1986,15(1):37-47
We have investigated two major aspects of the pulmonary host defense mechanism--alveolar macrophage function as a "first line of bacterial defense" and induced neutrophil migration into the lung as a "back-up defense." Chemotactic and phagocytic/killing assays revealed a functional deficiency in the alveolar macrophages of newborn primates. Serial bronchoalveolar lavage investigations revealed diminished neutrophil migration into the newborn primate lung. The overall pulmonary host defense capability in newborn primates was deficient. The results of this investigation may have direct clinical relevance to the susceptibility of newborns to infections and pneumonia. 相似文献
9.
Human Evolution - Four Types of precision holding in the human hand have been identified and described in accordance with the contrasting regional properties of a differentiated ungual pulp of the... 相似文献
10.
Olga O. Blumenfeld Anthony M. Adamany Karen V. Puglia Wladyslaw W. Socha 《Biochemical genetics》1983,21(3-4):333-348
Chimpanzee erythrocytes express strong M but weak, occasional N blood-group activity, as detected by anti-M and anti-N reagents. We have found that the M activity is carried by a major membrane glycoprotein that is similar but not identical to the human MM glycoprotein (glycophorin A). We have isolated and characterized this glycoprotein from erythrocyte membranes of four individual chimpanzees. The purified glycoproteins strongly inhibited agglutination of M cells by rabbit anti-human M sera and only weakly inhibited the agglutination of N cells by rabbit anti-human N sera. They also displayed medium-to-strong inhibitory activity against chimpanzee iso- and crossimmune antisera tested with chimpanzee erythrocytes of various V-A-B-D and Wc specificities, which are known as chimpanzee extensions of the human type M-N system and the Miltenberger counterpart, respectively. Each glycoprotein was cleaved with CNBr into three fragments, whose size, solubility, and composition were analogous to those obtained by similar treatment of the human M-N antigens. The amino-terminal fragment was found to be a glycooctapeptide whose amino acid composition and partial sequence indicated that it is an intermediate form of the human M and N glycooctapeptides. Its carbohydrate content comprised two threonine-linked saccharide units that, although similar in composition to the human threonine-linked units, were fewer in number than the three units found in the corresponding human glycooctapeptides. Structural similarities to the human antigens strongly suggest that the amino terminus bears the major antigenic determinants of the molecule, and the occurrence in this region of numerous, albeit rare, variants among humans and in chimpanzees indicates that the corresponding coding sequence of the structural gene is particularly susceptible to mutational events. We conclude that the chimpanzee M gene product is a variant of the human type and that the chimpanzee gene is an allele of the human polymorphic M-N locus.This research was supported by National Institutes of Health Grants GM 16389 and HL 19011 and March of Dimes Grant 1-661. 相似文献