Parthenogenesis, or virgin birth, describes a mode of reproduction where an egg develops into an offspring without fertilization, and is observed across various vertebrate taxa, excluding mammals. Obligate parthenogenesis, found in around 100 vertebrate species and 1000 invertebrate species, is relatively rare. Conversely, facultative parthenogenesis, where females can reproduce both sexually and parthenogenetically, is observed in some vertebrates, including elasmobranchs.
View Article and Find Full Text PDFCarabus (Cathoplius) aliai was described as a separate species by Escalera in 1944 but since the 1950-60s it has been considered as a subspecies of Carabus (Cathoplius) stenocephalus Lucas, 1866. This downgrading was adopted after examining only a few specimens, due to their rarity in collections. In recent years, an important population of this taxon was rediscovered in the Tan-Tan area in southern Morocco.
View Article and Find Full Text PDFAccording to current taxonomy, Subgenus Cathoplius C.G. Thomson, 1875, within the Genus Carabus Linnaeus, 1758 (in the broad sense), includes two species: C.
View Article and Find Full Text PDFBy constructing a biological model based on in vitro culture of polarized rainbow trout primary skin epithelial cell monolayers, the series of early events that precede Streptococcus iniae infection, particularly colonization and translocation through external barriers, were analyzed. Streptococcus iniae promptly invades skin epithelial cells, but the rapid decline of viable intracellular bacteria points out the limited capability of intracellular survival for this bacterium. Translocation assays, supported by electron microscopy microphotographs, demonstrate that following successful in vitro invasion of skin epithelial cell, the bacterium exists free in the cytoplasm after release from the endosome, and translocates through the skin barrier.
View Article and Find Full Text PDFAppl Environ Microbiol
September 2004
Infection with Lactococcus garvieae is considered the most important risk factor for the European trout industry, and the losses are approximately 50% of the total production. To improve our understanding of the genetic links among strains originating from different countries, we examined the population structure of L. garvieae by comparing 81 strains isolated from different sources and ecosystems (41 farms in six countries) in which the bacterium is commonly found.
View Article and Find Full Text PDFThe salmonid macrophage-like cell line RTS-11 and purified trout pronephros phagocytes were used to analyze in vitro entry and survival of two Streptococcus iniae serotypes. Efficient invasion by S. iniae occurred in both cells, but only the type II strain persisted in pronephros phagocytes for at least 48 h.
View Article and Find Full Text PDF