Only females were observed in Spasalus crenatus (Mac Leay 1819) in the Antilles, from Puerto Rico to Saint-Vincent, whereas both sexes are in Trinidad and on the continent. No difference in endo- and ectodermic female genitalia could be noticed between the two populations. Chromosomes of specimens from Guadeloupe reveal a 26,XX karyotype, as in females of various sexual species of Passalini, which demonstrates its diploidy. Breedings were developed with isolated immature stages. After nine years, descendants from a single female are demonstrating their parthenogenetic reproduction. This is the first recorded parthenogenesis in Passalidae and a rare telytoky in diploid insects. Relationships between parthenogenesis, diploidy and insularity are discussed in the scheme of geographical parthenogenesis. No discriminant morphological character on adults could be found between the two populations, except the total length. The modes of reproduction distinguishing the two geographically separated populations suggest the presence of two taxa: S. crenatus on the continent and Trinidad; the parthenote S. puncticollis (Le Peletier & Serville 1825), n. stat., on the Arc of the Antilles.
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http://dx.doi.org/10.1016/j.crvi.2015.09.001 | DOI Listing |
Comp Cytogenet
December 2024
Zoological Institute of the Russian Academy of Sciences, Universitetskaya Emb. 1, Saint Petersburg, 199034, Russia Zoological Institute of the Russian Academy of Sciences Saint Petersburg Russia.
The paper elaborates theoretical basis of the origin of aphid cyclical parthenogenesis in view of the original life of these insects in strobiloid galls on spp. The period of gall opening is greatly extended in time, which prevents normal panmixia and creates a selective advantage for parthenogenetic reproduction. Migration of aphids to secondary host plants, on which closed galls never form, parthenogenetic reproduction on these plants, and the subsequent simultaneous return of "remigrants" to the main host plant make it possible to synchronize the development of the bisexual generation and achieve mass panmixia at the end of the life cycle only; it coincides with the end of summer growth shoots or the autumn end of the vegetation period as a whole.
View Article and Find Full Text PDFEvolution
December 2024
Evolution and Ecology Research Centre, School of Biological, Earth and Environmental Sciences, University of New South Wales Sydney, Sydney, New South Wales, Australia.
Facultatively parthenogenetic animals could help reveal the role of sexual conflict in the evolution of sex. Although each female can reproduce both sexually (producing sons and daughters from fertilized eggs) and asexually (typically producing only daughters from unfertilized eggs), these animals often form distinct sexual and asexual populations. We hypothesized that asexual populations are maintained through female resistance as well as the decay of male traits.
View Article and Find Full Text PDFSci Total Environ
December 2024
Amsterdam Institute for Life and Environment (A-LIFE), Faculty of Science, Vrije Universiteit Amsterdam, De Boelelaan 1108, 1081 HZ Amsterdam, the Netherlands. Electronic address:
An estimated 467 kt of plastic used in agriculture annually end up in European soils, potentially breaking down into secondary microplastics (MPs). Not much is known about the possible effects of these MPs on organisms residing in the soil. To properly assess their environmental risk, experimental data is needed on the toxicity of MPs to the survival and reproduction of model organisms.
View Article and Find Full Text PDFGynecol Oncol Rep
December 2024
Department of Obstetrics, Gynecology and Reproductive Sciences, Yale School of Medicine, New Haven, CT, USA.
Background: Uterine teratomas are a rare entity with a debated origin. Given its rarity and limitations of diagnostic imaging, diagnosis is typically determined pathologically following surgical resection based on the presence of tissue derived from all germ cell layers. Unlike its ovarian counterpart, the developmental origins are poorly understood; however, recently introduced molecular testing has revolutionized our understanding of these rare tumors.
View Article and Find Full Text PDFExp Anim
November 2024
Laboratory of Animal Reproduction, College of Agriculture, Kindai University.
After in vitro maturation (IVM) of porcine germinal vesicle (GV) oocytes, those that matured to the metaphase II (MII) stage were selected for further culture over a period of 24-48 h. Subsequently, these oocytes were either parthenogenetically activated or used for somatic cell nuclear transfer (SCNT) to evaluate their in vitro developmental competence. Parthenogenetically activated MII oocytes developed to the blastocyst stage after 42 h of continuous culture, whereas SCNT oocytes reached the blastocyst stage within 30 h of culture.
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