Social dominance regulates androgen and estrogen receptor gene expression

In Astatotilapia burtoni, dominant males have higher levels of sex steroid hormones than subordinate males. Because of the complex regulatory interactions between steroid hormones and receptors, we asked whether dominance is also associated with variation in sex steroid receptor gene expression. Using quantitative PCR, we compared the expression of specific subtypes of androgen (AR) and estrogen (ER) receptor genes between dominant and subordinated males in 3 divisions of the brain, the pituitary, and the testes. We measured mRNA levels of AR-alpha, AR-beta, ER-alpha, ER-betaa, and ER-betab, gonadotropin-releasing hormone 1 (GnRH1), and GnRH receptor 1 (GnRH-R1) relative to 18S rRNA. In the anterior part of the brain, we found that dominant males had higher mRNA expression of AR-alpha, AR-beta, ER-betaa, and ER-betab, but not ER-alpha, compared to subordinate males. This effect of dominance was reflected in a positive correlation between testes size and AR-alpha, AR-beta, ER-betaa, and ER-betab in the anterior brain. In addition, mRNA levels of all ARs and ERs in the anterior brain were positively correlated with mRNA level of GnRH1. In the middle and posterior portions of the brain, as well as the testes, steroid receptor mRNA levels were similar among dominants and subordinates. In the pituitary, ER-alpha mRNA level was positively correlated with testes size and AR-alpha mRNA was positively correlated with GnRH-R1 mRNA level. These data suggest that dominant male brains could be more sensitive to sex steroids, which may contribute to the increased complexity of the behavioral repertoires of dominant males.     

Inactivation of the medial preoptic area or the bed nucleus of the stria terminalis differentially disrupts maternal behavior in sheep

The present study was designed to investigate the role of the medial preoptic area (MPOA) and the bed nucleus of the stria terminalis (BNST) in the onset and maintenance of maternal behavior in sheep. In a first experiment, the MPOA or BNST were transiently inactivated during the first 2 h postpartum in primiparous ewes with the use of the anaesthetic lidocaine. MPOA inactivation greatly impaired the display of maternal behavior whereas inactivation of BNST or of adjacent sites (septum or diagonal band of Broca) or infusion of cerebrospinal fluid did not. In a separation/reunion lamb test (S/R) performed at 2 h postpartum, ewes with MPOA inactivation exhibited little reaction after separation of their lambs and did not show any motivation to reunite with them. Ewes with BNST inactivation showed intermediate performances in the S/R test. Moreover, in control ewes that were maternal for the first 2 h postpartum, MPOA or BNST inactivation performed in the following 12 h induced deficits in the S/R test, indicating that the MPOA and to a lesser extent BNST are also involved in the maintenance of maternal behavior. A second experiment showed that, in multiparous ewes, MPOA inactivation at parturition induced less deficit in the display of maternal behavior and in the S/R test than in primiparous mothers. These findings indicate that the MPOA and, to some extent, the BNST are functionally involved in the initiation and in the maintenance of maternal behavior in sheep, but this involvement is influenced by maternal experience.     

Does kin structure explain the occurrence of workers in a lower termite?

Kinship plays a fundamental role in the origin of social life. It is also predicted to affect numerous details within animal societies, yet recent studies revealed equivocal results. We tested the influence of relatedness for the occurrence of workers in the termite Cryptotermes secundus. Here individuals are developmentally flexible to remain workers or to become dispersing sexuals that found new colonies. Furthermore, colony relatedness naturally increases with inbreeding and decreases when neighboring colonies fuse. Similar to recent studies on social Hymenoptera, our experimental change in relatedness gave equivocal results. Reducing relatedness within colonies did not have an effect, but individuals in inbred colonies were less likely to disperse and more likely to remain workers as predicted by kinship arguments. Several explanations for the interpretation of these equivocal results are provided.     

Familiarity and partner preferences in female common voles, <Emphasis Type="Italic">Microtus arvalis</Emphasis>

Captive female common voles (Microtus arvalis) had a clear social preference for familiar males in a standard preference test. Cohabitation for a short period resulted in preferences for familiar partners, and females spent eight times more time in body contact with a familiar male than with an unfamiliar male. Females also displayed stranger-directed aggression. Our results suggest that the common vole is a species with selective partner preferences and a tendency to form tight social relationships and stable male–female associations.     

Social control of terminal phase transition in primary males of the diandric wrasse, <Emphasis Type="Italic">Halichoeres poecilopterus</Emphasis> (Pisces: Labridae)

In many diandric fishes, large territorial males with bright body coloration (terminal phase (TP) males) are derived either from initial phase (IP) females that change sex to male or from IP primary males that change color and behavior, but do not change sex. The mechanism controlling the transition of IP primary males into TP males is not well understood. We conducted cohabitation experiments to examine social conditions favoring TP transition by primary males in the diandric wrasse, Halichoeres poecilopterus. IP primary males always started TP-specific sexual behavior in the presence of a smaller subordinate, and subsequently acquired TP body coloration. In contrast, primary males under subordinate conditions often performed female-like sexual behavior. In pairs with similar body sizes, both individuals initiated TP male behavior. The results suggest that TP transition in primary males may be closely related to a dominance relationship (or size order) within social groups, as it is in the case of sex change by females.     

Identification and domain mapping of Dictyostelium discoideum type-1 protein phosphatase inhibitor-2

The protein phosphatase type-1 catalytic subunit (PP1c) does not exist freely in the cell and its activity must be very strictly controlled. Several protein inhibitors of PP1c have been described including the classical mammalian inhibitor-1 (I-1) and inhibitor-2 (I-2). Association of these inhibitors with PP1c appears to involve multiple contacts and in the case of I-2 no less than five I-2 interaction subdomains have been proposed. In this report, we provide both in vitro and in vivo evidence that the Dictyostelium discoideum genome encodes a protein (DdI-2) that is an ortholog of mammalian I-2, being the first PP1c interacting protein characterized in this social amoeba. Despite the low overall sequence similarity of DdI-2 with other I-2 sequences and its long N-terminal extension, the five PP1c interaction motifs proposed for mammalian I-2 are reasonably conserved in the Dictyostelium ortholog. We demonstrate that DdI-2 interacts with and inhibits D. discoideum PP1c (DdPP1c), which we have previously characterized. Moreover, using yeast two-hybrid assays we show that a stable interaction of DdI-2 with DdPP1c requires multiple contacts.     

From “Shrinks” to “Urban Shamans”: Argentine Immigrants’ Therapeutic Eclecticism in New York City

This article examines Argentine immigrants' reliance on informal networks of care that enable their access to a variety of health providers in New York City (NYC). These providers range from health brokers (doctors known on a personal basis) to urban shamans, including folk healers and fortunetellers of various disciplines. A conceptual framework, based on analysis of social capital categories, is proposed for the examination of immigrants' access to valuable health resources, which are based on relationships of reciprocity and trust among parties. Results revealed immigrants' diverse patterns of health-seeking practices, most importantly their reliance on health brokers, epitomized by Argentine and Latino doctors who provide informal health assistance on the basis of sharing immigrants' social fields and ethnic interests. While mental health providers constitute a health resource shared by Argentines' social webs, urban shamans represent a trigger for the activation of women's emotional support webs. Contrary to the familiar assumption that dense and homogenous networks are more beneficial to their members, this article underscores the advantages of heterogeneous and fluid social webs that connect immigrants to a variety of resources, including referrals to diverse health practitioners.     

The Fundamental Constraint on the evolution of culture

This paper argues that there is a general constraint on the evolution of culture. This constraint – what I am calling the Fundamental Constraint – must be satisfied in order for a cultural system to be adaptive. The Fundamental Constraint is this: for culture to be adaptive there must be a positive correlation between the fitness of cultural variants and their fitness impact on the organisms adopting those variants. Two ways of satisfying the Fundamental Constraint are introduced, structural solutions and evaluative solutions. Because of the limitations on these solutions, this constraint helps explain why there is not more culture in nature, why the culture that does exist has the form it has, and why complex, cumulative culture is restricted to the human species.     

社会网络分析方法在鸟类物种多样性分析中的应用——以董寨国家级自然保护区5.5 d环志数据为例北大核心CSCD

本研究通过社会网络分析网捕环志的数据,来调查河南董寨国家级自然保护区的鸟类物种多样性以及鸟类物种的集群特征。在2021年10月连续5.5 d的网捕环志中,总共环志12科33种鸟类,其中环志最多的鸟类物种为棕头鸦雀(Sinosuthora webbiana)、红胁绣眼鸟(Zosterops erythropleurus)和强脚树莺(Horornis fortipes)。33个物种中树栖食虫鸟类最多,共12个物种,其次是地表食虫鸟类(共8个物种)和杂食鸟类(共6个物种);留鸟17种和迁徙鸟类16种。通过社会网络分析,发现种群数量多的物种处于社会拓扑网络的中心位置,而且相同食性生态位的物种连结强度很高,如树栖食虫鸟类。结果表明,物种种群数量、食性生态位对鸟类物种社会网络关系的影响较大,而物种迁徙特征对鸟类物种社会网络关系则几乎没有影响。本文在国内尝试了采用社会网络分析来调查当地鸟类物种群落的多样性,并揭示了鸟类多物种集群的关键驱动因子。对比传统的鸟类群落调查方法,多物种社会网络分析可获取该集群的时空分布以及物种之间的相互联系。由于社会网络分析可以分析和研究不同生物水平包括个体、种群、物种等的社会行为,从而使之成为近年来很多生物研究领域的常用和热点工具。     

圈养林麝的活跃性及与社会亲和度的关系

采用扫描取样和焦点动物取样法对四川马尔康林麝繁育场的45头圈养林麝进行行为取样,以其非静息行为的发生率作为活跃性指标,以社会亲和行为的发生强度作为社会亲和度指标,分析圈养林麝活跃性与其性别、圈群密度及社会亲和度的关系。结果表明:圈群密度和社会亲和度对圈养林麝的活跃性有显著影响(P < 0.05),但活跃性雌雄差异不显著(P > 0.05)。与高密度圈群的林麝(0.25 ± 0.021, n=32)相比,低密度圈群中的个体更活跃(0.40 ± 0.022, n = 4);活跃性与社会亲和度之间显著相关(r = 0.390, P = 0.01),活跃性较高个体倾向于展现高的社会亲和度。建议麝场在进行麝群构建时,充分考虑林麝个体的活跃性差异及与圈群密度的关系,以提高圈群稳定性和驯养生产力。