NESTMATE RECOGNITION AND KIN RECOGNITION IN ANTS

Abstract  All ants (Hymenoptera, Formicidae) are highly eusocial insects that are characterized by reproductive division of labor with sterile castes (worker and soldier) helping fertile castes (queen and male) to reproduce.
Ant societies, like other complex animal societies, have developed a sophisticated communication system, in which recognition behaviors are frequently involved Recognition abilities allow individuals to orient and modulate their behaviors effectively and appropriately in response to the characteristics andlor signals expressed by other organisms. Among recognition behaviors, nestmate recognition and kin recognition mechanisms have attracted great attention of sociobiologists, ecologists, insect physiologists and biochemists since 1970's. This is parallel with the popularization of Hamilton's kin selection theory. The present paper aims at reviewing the current understanding on nestmate/kin recognition in ants. This review consists of three parts. The first part concerns the diversity of recognition behaviors and their ecological implications with emphasis on nestmatelkin recognition; in the second part, the current understandings on the mechanism of nestmatelkin recognition are outlined; and in the third part, we discuss the ontogenetic development of nestmate recognition behavior and naturally mixed colonies. The study of the integration mechanism of social parasite may provide heuristic clues to the understanding of kin/nestmate recognition system.     

Developmental changes of glucocorticoid receptors in the rat pancreas

Glucocorticoids are known to play a role in the maturation of the exocrine pancreas. The exact mechanism of glucocorticoid action in pancreatic ontogeny is, however, not clear. The present study characterized and quantitated the binding of [3H]dexamethasone to cytosol fractions from pancreata of rats at various ages. Trunk blood samples from these rats were also checked for levels of free and bound corticosterone. Specific and saturable bindings for dexamethasone were found in pancreatic cytosol fractions from newborn suckling and adult rats. Competition studies showed a preference for steroids with glucocorticoid activity. Specific binding was relatively low in pancreatic cytosol from newly born and 1-day old pups. A significant rise was seen after day 15. Cytosolic binding capacities were greatest from pancreata obtained from pups at weaning (3rd to 5th weeks). Values then declined toward the adult level. Scatchard analysis revealed a single class of binding sites with a dissociation constant (Kd) of 7.3 (+/- 1.1) X 10(-8) M and number of binding sites equalled to 1.29 (+/- 0.18) X 10(-13) mole/mg of cytosolic protein in adult rat pancreas. Pancreata from 25- and 15-day old rats had Kds of 3.4 (+/- 0.8) X 10(-8) M and 2.7 (+/- 0.7) X 10(-8) M with the number of binding sites equal to 1.77 (+/- 0.21) X 10(-13) mole/mg protein and 1.31 (+/- 0.16) X 10(-13) mole/mg protein respectively. Total plasma corticosterone concentration was low before day 10. It rose significantly by day 15, peaked at day 25, and then declined after weaning. About 5-15% of corticosterone during weaning and about 20-30% before and after weaning were in the free form. The peak level of dexamethasone binding corresponded to an increase in the plasma corticosterone level during weaning. This suggests a close relationship between plasma corticosterone levels and pancreatic glucocorticoid receptors. Both may, therefore, play a role in pancreatic development in the rat.     

Influence of GATC sequences on Escherichia coli DNA mismatch repair in vitro.

The effect of the number and position of DNA adenine methylation (dam) sites, i.e., d(GATC) sequences, on mismatch repair in Escherichia coli was investigated. The efficiency of repair was measured in an in vitro assay which used an f1 heteroduplex containing a G/T mismatch within the single EcoRI site. Both an increase in the number of dam sites and a shortened distance between dam site and mismatched site increased the efficiency of mismatch repair. The sequences adjacent to d(GATC) also affected the efficiency of methylation-directed mismatch repair. Furthermore, heteroduplexes with one extra dam site located close to either the 5' or 3' end of the excised base increased the repair efficiency to about the same extent. The findings suggest that the mismatch repair pathway has no preferred polarity.     

孕马血清促性腺激素和氯地酚对猕猴超数排卵效果的观察

用孕马血清促性腺激素,总剂量为1550—2000单位,分4—7天处理猕猴,可促使其每侧卵巢出现滤泡超数发育,随后静脉注射入绒毛膜促性腺激素2500单位,在24小时内,猕猴即可出现超数排卵。     

中国毛角隐翅虫属一新种及一新纪录(鞘翅目:隐翅甲科, 毛角隐翅虫亚科)

毛角隐翅虫属(Trichophya Mannerheim 1830)系毛角隐翅虫亚科(TrichophyinaeGanglb.1895)的单一属。模式种为Trichophya pilicornis Gyllenhal。根据触角着生在眼的前方,11节,第1、2节很膨大,第3节以后细长如线,各节环生长毛;鞘翅缘折无与背面分隔的脊;跗节5节;腹后部渐尖等属征,不难与别的隐翅虫属区分。该属为一小属,全世界已知10种,T.pilicornis Gyll.分布全北区及东洋区;T.lativentris Casey, T.tars-     

白兰瓜果实输入~(14)C-葡萄糖的转化与蔗糖合成

~(14)C 追踪试验结果表明,白兰瓜幼果中输入的~(14)C-葡萄糖,50%以上转化为稀酸水解和稀酸不水解的结构物质;果实发育后期,输入后48小时,在果肉和种子中分别只有18%和32%的~(14)C 参入结构物质。根据醇溶性糖的纸层析鉴定,幼果薄片渗入的~(14)C-葡萄糖仅转化为果糖,而发育后期果实则更多转化为蔗糖。显然,幼果的代谢模式是使物质和能量导向结构物质的形成;而后期果实生长已基本停止,物质代谢的方向又转向蔗糖合成的轨道上来。蔗糖合成底物试验结果表明,供给幼果不同底物都只有很低的蔗糖合成活性;发育后期果实供给UDPG+F-6-P 底物时可测出较高的蔗糖合成活性,初步推测白兰瓜中蔗糖合成主要是通过蔗糖磷酸酯合成酶来实现的。     

异大茴香脑新资源——齿叶黄皮的研究

齿叶黄皮是生长于广东省北部石灰岩山地的一种芸香科常绿小乔木,其叶富含精油,枝叶经水蒸汽蒸馏出油率为0.7%。精油经毛细管气相色谱、气相色谱/质谱联用、红外吸收光谱、核磁共振波谱等方法分析,确证含异大茴香脑(isoanethole)93.10%。异大茴香脑对霉菌有较强抑菌活性,并可通过异构化一步转变为大茴香脑。     

Formation of lymphocyte colonies under serum-free culture conditions in normal individuals and patients with chronic lymphocytic leukemia

This paper describes a culture system which supports the formation of B cell and some T cell colonies under serum-free conditions in peripheral blood samples of normal individuals and patients with chronic lymphocytic leukemia (CLL) of B cell type. In this system, serum is replaced by bovine serum albumin, transferrin, cholesterol, insulin and catalase or horseradish peroxidase. In addition, it is necessary to add staphylococcus protein A, mitomycin-treated T cells as feeders and phytohemagglutinin leukocyte-conditioned medium as a source of growth factors. The plating efficiency is greatly enhanced when normal cells are incubated with galactose oxidase prior to plating and when CLL cells are exposed sequentially to neuraminidase and galactose oxidase.