第20回GCOE国際セミナー

2014年2月3-5日の午後から箱崎キャンパス理学部3号館5階の生物第3会議室(3日)とシステム生命科学棟1階のセミナー室(4,5日)にて、ベル ギーのLeuven UniversityのJohan Billenさんをお招きして、アリなど社会性昆虫の外分泌腺・貯精嚢の機能形態学や道しるべフェロモンによる化学コミュニケーション、樹脂切片標本の作 成などについてお話して頂きます。多くの方々の参加をお待ちしております。

講師:Johan BillenLeuven University, Belgium

日時:201423日~5日の15時~17時(4日は1330分~)

場所:3日 理学部3号館5階の生物第3会議室

45日 システム生命科学府棟1階のセミナー室

 

201423日(月)15:0017:00(理学部3号館5階の生物第3会議室)

 アリの外分泌腺の機能形態学

 

201424日(火)13:3017:00(システム生命科学府棟1階のセミナー室)

アリにおける動員と道しるべフェロモン

 社会性昆虫の貯精嚢の機能形態学

※途中休憩を30分ほどいれます。

 

201425日(水)15:0017:00(システム生命科学府棟1階のセミナー室)

 樹脂切片標本作成について

 

なお、本セミナーはGCOEアジア保全生態学コース授業科目「国際セミナーI, II

D1, D2の必修科目)の一環として行われます。

この科目では、一年間を通じて少なくとも2回はセミナーに出席することが単位取得要件と

なっています。

事業推進担当者の先生方や特任スタッフの皆様には、対象となる院生への周知を

よろしくお願いいたします。

 

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The 20th GCOE International Seminar

Date: 3-5 Feb 2014

Time: 3rd: 15:00 ~ 17:00

         4th: 13:30 ~ 17:00

         5th: 15:00 ~ 17:00

Place: 3rd: Meeting Room #3 on 5th floor of Faculty of Sciences Building #3

           4th: Seminar Room (1st floor) of Graduate School of System Life Sciences

           5th: Seminar Room (1st floor) of Graduate School of System Life Sciences

Lecturer: Dr. Johan Billen, Leuven University, Belgium

 

Talk Title: 3rd Feb: Diversity and functional morphology of exocrine glands in ants

4th Feb: Recruitment and trail pheromone in ants

Functional morphology of the spermatheca in social insects

               5th Feb: Technical steps in tissue preparation for microscopy


Abstract

Diversity and functional morphology of exocrine glands in ants

Bees, wasps, ants and termites are fascinating because of their well organized societies. Among the characteristics of social insects is the occurrence of a great diversity of exocrine glands. The high number of these glands goes along with the various functions their products play. To date, this variety amounts to 130 different glands that can be distinguished among the various social insect groups, with ants the most diverse group with 89 known glands. The glands can be classified in five main groups according to their anatomical organization. This talk brings a survey of the structural and functional diversity of exocrine glands in ants, using selected examples that represent the main gland types. These examples at the same time also illustrate the big variety of functions the glandular secretions can play. A very well known function is that of producing the various pheromonal substances, that play a role in the communicative interactions between nestmates (such as alarm, trail, recruitment, sex pheromones…). Other known functions of exocrine gland secretions deal with reproduction and caste determination, or with the elaboration of antibiotic substancess, digestive enzymes and saliva, nest material and lubricants

Orientation and recruitment in ants

Foraging ants display various mechanisms to find the way between their nest and food sources or new nest locations. Visual orientation is known in several species, such as Formica wood ants and Cataglyphis desert ants. Most common, however, are the chemically marked trajectories using trail pheromones. A primitive type of trail following is found in tandem running, in which one leader recruits and leads a single nestmate at a time to the food source. More evolved are the mass trails, in which hundreds to thousands of ants follow and reinforce the trail. The pheromonal substances involved are perceived with the antennae, and are produced by a variety of exocrine glands. These glands are located either in the abdomen or in the hindlegs. This talk illustrates the variety of multiple anatomical origins with examples of several trail-following ant species: leaf-cutting ants lay trails with their venom glands, whereas fire ants use Dufour gland secretions. Each of the three army ant groups has a different gland producing the trail substances (venom gland in Dorylinae, a sternal epithelium in Ecitoninae and postpygidial gland in Aenictinae). Other species, such as Crematogaster ants, drag their hindlegs over the substrate during the process of trail-laying, and use secretions from hindleg glands trail marking.

Functional morphology of the spermatheca in social insects

Since mating is a unique event that occurs in the very first weeks of the queen’s adult life, and considering that social insect queens can reach lifespans of several years, sufficient quantities of sperm for their entire life need to be stored and kept viable after copulation. The spermatheca fulfills this crucial role, and therefore represents an organ that is of particular importance in the reproductive biology. The spermatheca consists of a rounded reservoir, that is connected to the oviduct through a sperm duct. The ducts from two spermathecal glands open into the spermathecal duct near to its connection to the reservoir. This region of the spermathecal duct is characterized by an extensive muscular supply or ‘sperm pump’, that regulates the amount of sperm that is released to fertilize eggs that pass through the oviduct. Queens possess a functionally active spermatheca, while workers either lack it, or have a non-functional spermatheca. This clear distinction between fertile queens and sterile workers becomes more subtle in some phylogenetically basal ant species. Workers of such species may be reproductively active as well, as they are able to mate and produce worker offspring. Our work shows that the presence of a metabolically active epithelium in at least part of the reservoir wall is a crucial condition for the spermatheca to be functionally active. Secretions from these active cells may provide nutrients to keep the stored sperm cells viable, while the spermathecal glands are thought to activate metabolically arrested sperm cells, thus enabling them to move towards the oviduct. 

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