糖在猕猴精子低温冷冻保存过程中的作用

TTE或TEST防冻液在冻存猕猴精子时产生不同结果,其主要不同在于防冻液中糖成分的不同。本实验利用透射电镜技术检测这2种防冻液冻存的猕猴精子冷冻前后超微结构的变化,以说明糖在低温冻存过程中的作用。结果表明,冷冻复苏过程对精子结构产生了影响。TTE法低浊保存的猕猴精子的头部的质膜出现少许皱褶或泡化现象,但精子的顶体、核或是精子尾部的结构与鲜精的结构基本相似。猕猴精子经TEST法低温保存后,大部分精子结构则发生了明显的变化。精子膜、顶体和精子核明显泡化、损伤或破裂,精子尾部不能分辨出正常的超微结构。这提示,可能由于TTE防冻液中复杂的糖成分在降温／复苏过程对精子起到了较好的协同冷冻保护作用;而TEST防冻液中单一的糖成分不能完全保护精子避免低温损伤,低温保存过程破坏了精子的结构,并影响了复苏后精子体外存活能力与受精能力。     

Supra-annual variation in the influence of Myrica rubra fruit on the behavior of a troop of Japanese macaques in Yakushima

Observations were made on a well-habituated natural troop of Japanese macaques (Macaca fuscata yakui), living in warm-temperate, lowland forest in Yakushima. Between mid-May and the end of June the macaques feed on the fruit of the evergreen tree Myrica rubra (Myricaceae). The fruit of this species are abundant in some years and scarce in others. Data were compared for two heavy-fruiting years (1988 and 1990) and one poor-fruiting year (1991) to examine the influence of fruit availability on patterns of foraging, ranging, and the frequency of inter-troop encounters. In both heavy-fruiting years M. rubra fruit accounted for a maximum of over 70% of foraging time, compared with a maximum of <5% in the poor-fruiting year. Heavy fruiting was also associated with a marked decrease in the overall time spent foraging. In early May of all three years troop movements were largely confined to northern parts of the home range. By early June of both heavy-fruiting years ranging had shifted to the south-west, and included an area with a high concentration of M. rubra trees. This area was rarely visited at other times, and was not visited during the study period in the poor-fruiting year. The overlap in range-use between the two heavy-fruiting years was significantly greater than that between the heavy-fruiting years and the poor-fruiting year. Heavy fruiting was also associated with an increase in the frequency of inter-troop encounters. © 1995 Wiley-Liss, Inc.     

Normal serum biochemical and hematological parameters in Macaca fascicularis.

The effects of age, sex, pregnancy, were analyzed and data from fasted and fed animals were compared in a population of cynomolgus macaques. No significant sex effects were observed for biochemical values and no changes were found in male hematological parameters in relation to age. Most values of females during pregnancy were within normal ranges. Comparison between fed and fasted animals showed that several biochemical parameters (e.g., ALT, glucose, CPK, LDH) and several hematological parameters (e.g., monocytes, eosinophils, basophils, hemoglobin, MCV, MCHC, and MCH) were affected by food intake.     

A statistical analysis of the social behavior of the male stumptail macaque (Macaca arctoides)

The social behavior of male stumptail macaques was analyzed in terms of behavioral sequences recorded during paired encounters in a large test cage. Recurrent patterns of behavioral sequences were sought and used to hypothesize the structure of motivational systems of social behavior as has been done previously for other species. In addition to traditional statistical analyses to determine which dyadic behavioral sequences were nonrandom, there were several methodological innovations. Instead of analyzing behavior as a single channel of communications, we analyzed three independent channels and considered their inter-correlations: 1) acts and postures; 2) vocalizations; and 3) facial expressions. Also, we analyzed not only within-animal behavioral sequences but between-animal sequences as well. Results were derived from 40 tests, most of which included vigorous agonistic and sexual interactions and a behavioral repertoire similar to that of adult male stumptail macaques observed by previous investigators. There were 30 acts and postures, eight facial expressions, and seven vocalizations that occurred more than five times. Many acts and postures occurred in nonrandom sequences, 43 such sequences within-animal and 40 between-animal. From these sequences and their correlations with specific vocalizations and facial expressions, it was possible to differentiate six categories of social behavior that may correspond to six different motivational systems: offense, defense, submission, groom and contact, male sexual behavior, and display. Both the frequency of behaviors in each category and the nature of the behavioral sequences were affected by the relative dominance of the two animals.     

The development and ecology of the Japanese macaque gut microbiome from weaning to early adolescence in association with diet

Previously we have shown that the Japanese macaque gut microbiome differs not by obesity per se, but rather in association with high‐fat diet (HFD) feeding. This held true for both pregnant dams, as well as their 1‐year‐old offspring, even when weaned onto a control diet. Here we aimed to examine the stability of the gut microbiome over time and in response to maternal and postweaning HFD feeding from 6 months of age, and at 1 and 3 years of age. In both cross‐sectional and longitudinal specimens, we performed analysis of the V4 hypervariable region of the 16S rRNA gene on anus swabs collected from pregnant dams and their juveniles at age 6 months to 3 years (n = 55). Extracted microbial DNA was subjected to 16S‐amplicon‐based metagenomic sequencing on the Illumina MiSeq platform. We initially identified 272 unique bacterial genera, and multidimensional scaling revealed samples to cluster by age and diet exposures. Dirichlet multinomial mixture modeling of microbiota abundances enabled identification of two predominant enterotypes to which samples sorted, characterized primarily by Treponema abundance, or lack thereof. Approximating the time of initial weaning (6 months), the Japanese macaque offspring microbiome underwent a significant state type transition which stabilized from 1 to 3 years of age. However, we also found the low abundance Treponema enterotype to be strongly associated with HFD exposure, be it during gestation/lactation or in the postweaning interval. Examination of taxonomic co‐occurrences revealed samples within the low Treponema cluster were relatively permissive (allowing for increased interactions between microbiota) whereas samples within the high Treponema cluster were relatively exclusionary (suggesting decreased interactions amongst microbiota). Taken together, these findings suggest that Treponemes are keystone species in the developing gut microbiome of the gut, and susceptible to HFD feeding in their relative abundance.     

Spectrographic analysis of laryngeal air sac resonance in rhesus monkey.

Laryngeal air sacs are circular out-pocketings, located in the hyoid bone with their ostium in the midline of the anterior part of the larynx. From previous cadaver studies of the rhesus monkey it was deduced that the function of the air sac is to act as a resonating chamber. The present study was designed to test this hypothesis. Recordings were made of three rhesus monkeys before and after surgical removal of the air sac. Spectrographic analysis of the monkeys' vocalizations indicated that differences in formant frequency characteristics between pre-and post-surgical recordings were negligible. This finding suggests that the laryngeal air sac does not play an important role in the resonant properties of the monkeys' vocal tracts.     

Intergroup transfer and incest avoidance in semifree-ranging barbary macaques (Macaca sylvanus) at Salem (FRG)

During a long-term study of social behavior of semifree-ranging Barbary macaques, data on group transfer and sexual behavior were collected. A large population containing five groups living in a 14.5 ha outdoor enclosure was studied. Demographic data on the whole population are available for a period of six years. Data on sexual behavior of members of one large group were collected, by both focal animal and ad libitum techniques, for a period of two years. Matrilineal kinship relations of all except the oldest members of this intensively studied group were known. Males changed groups most frequently between the ages of three and five years i.e., the time at which sexual maturity was reached. While more than 30% of all males three years old and older changed groups during the study period, many males remained members of their natal group even after reaching adulthood. However, sexual interactions, especially matings between close matrilineal relatives, were found to be almost absent, suggesting that Barbary macaques are not highly inbred as formerly supposed.     

Breaking cover: neural responses to slow and fast camouflage-breaking motion

Primates need to detect and recognize camouflaged animals in natural environments. Camouflage-breaking movements are often the only visual cue available to accomplish this. Specifically, sudden movements are often detected before full recognition of the camouflaged animal is made, suggesting that initial processing of motion precedes the recognition of motion-defined contours or shapes. What are the neuronal mechanisms underlying this initial processing of camouflaged motion in the primate visual brain? We investigated this question using intrinsic-signal optical imaging of macaque V1, V2 and V4, along with computer simulations of the neural population responses. We found that camouflaged motion at low speed was processed as a direction signal by both direction- and orientation-selective neurons, whereas at high-speed camouflaged motion was encoded as a motion-streak signal primarily by orientation-selective neurons. No population responses were found to be invariant to the camouflage contours. These results suggest that the initial processing of camouflaged motion at low and high speeds is encoded as direction and motion-streak signals in primate early visual cortices. These processes are consistent with a spatio-temporal filter mechanism that provides for fast processing of motion signals, prior to full recognition of camouflage-breaking animals.