Showing papers by "Fuminori Ito published in 2018"
TL;DR: This research identified genes that were up‐regulated in the male accessory glands relative to the bodies of Crematogaster osakensis to characterize the reproductive molecules associated with male reproductive success in ants and found novel genes that had no hits in a homology search and that were predominantly expressed in the accessory glands.
Abstract: In insects, seminal fluid proteins that are produced by male accessory glands and transferred to females during mating have key functions in sperm competition and sperm physiology that lead to male reproductive success. In ants, male reproductive success also depends on the longevity of sperm stored in the queen's spermatheca because their sexual offspring are usually produced only after a prolonged storage period. We identified genes that were up-regulated in the male accessory glands relative to the bodies of Crematogaster osakensis to characterize the reproductive molecules associated with male reproductive success in ants. We found novel genes that had no hits in a homology search and that were predominantly expressed in the accessory glands. These reproductive proteins may have evolved under rapid positive selection for reproductive success in the species. Furthermore, we discovered that three spermatheca-specific genes of C. osakensis queens were also enriched in the accessory glands relative to the bodies of males. These genes may be important for maintaining the sperm quality continuously from ejaculation by males to prolonged storage by queens. This research provides crucial information about the molecular mechanisms of sperm maintenance and sexual selection in ants, and also insight into the evolution of reproductive strategies in insects.
12 citations
TL;DR: Besides the common labial and metapleural glands, four novel exocrine glands are described in the thorax of both workers and queens of the ponerine ant Myopias hollandi, where ultrastructural examination indicates that they produce a non-proteinaceous and therefore possibly pheromonal secretion.
10 citations
Journal Article•
TL;DR: The present study presents biological observations on colony characteristics of Acanthomyrmex careoscrobis Moffett, 1986 in Ulu Gombak (Selangor, Malaysia), with redescription of the minor worker and descriptions of the hitherto unknown female castes and males.
Abstract: The present study presents biological observations on colony characteristics of Acanthomyrmex careoscrobis Moffett, 1986 in Ulu Gombak (Selangor, Malaysia), with redescription of the minor worker and descriptions of the hitherto unknown female castes and males. The colony of A. careoscrobis can produce both alate and ergatoid queens. Ergatoid queens may function as cheap secondary reproductive females, whereas it is at present unclear whether they engage in dependent colony foundation or not. Ergatoid queens have the same number of ovarioles as alate queens, and show variable intermediate external morphology between major workers and alate queens. The colony redistributes nutrients via trophic eggs among colony members. Reviewing current available data for other Acanthomyrmex species, this study highlights the great prevalence and diversity of ergatoid queens in this poorly-studied genus.
3 citations
TL;DR: It is shown that the cricket could not survive in artifical nests of the Argentine ant under laboratory conditions, and in the field, the cricket was never found in nests ofThe Argentine ant.
Abstract: Effects of the Argentine ant on myrmecophilous animals living inside ant nests have been rarely studied to date. We investigated whether the “specialist” myrmecophilous cricket Myrmecophilus kubotai Maruyama that lives only in colonies of a Japanese native ant, Tetramorium tsushimae Emery, could live with the Argentine ant. In the field, the cricket was never found in nests of the Argentine ant. Our experiments showed that the cricket could not survive in artifical nests of the Argentine ant under laboratory conditions.
2 citations
Journal Article•
TL;DR: The biology of six species of Aphaenogaster in Thailand is investigated, and their nesting habits and colony composition are investigated, suggesting they may also have important functions in at least some tropical ecosystems.
Abstract: The myrmicine ant genus Aphaenogaster comprises 187 valid species (Bolton 2016) and is distributed in the temperate to tropical zones throughout the world. They are dominant ant species in many temperate forest ecosystems, and hold important positions as predators and dispersers of myrmecochorous plants (Bednar et al. 2013, Caut et al. 2016, Higashi et al. 1987, Lubertazzi 2012, Mizutani & Imamura 1980, Ohara & Higashi 1987, Richards 2009, Thomas et al. 2016). Until now, our knowledge on the biology of Aphaenogaster ants has been limited to species in temperate regions. In the tropics, the species diversity of Aphaenogaster is thought to be low (cf. Brühl et al. 1998; Malsch et al. 2003), though the nest density of Aphaenogaster in some tropical areas can be quite high (see Results), suggesting they may also have important functions in at least some tropical ecosystems. However, the biology and ecology of tropical Aphaenogaster species remains largely unknown. In this study, we investigated the biology of six species of Aphaenogaster in Thailand, and report on their nesting habits and colony composition. SHORT COMMUNICATION