Structural and Functional Characteristics of the Centrosome in Gametogenesis and Early Embryogenesis of Animals

A Proximal Centriole-Like Structure Is Present in Drosophila Spermatids and Can Serve as a Model to Study Centriole Duplication

“…In vertebrates, the distal and proximal centrioles are mother and daughter centrioles, respectively (Krioutchkova and Onishchenko 1999). In numerous animals including fish, starfish, annelids, and mollusks, the proximal centriole is smaller than the distal centriole (Krioutchkova and Onishchenko 1999).…”

“…In vertebrates, the distal and proximal centrioles are mother and daughter centrioles, respectively (Krioutchkova and Onishchenko 1999). In numerous animals including fish, starfish, annelids, and mollusks, the proximal centriole is smaller than the distal centriole (Krioutchkova and Onishchenko 1999). The proximal centriole-like structure resembles a daughter centriole as it exhibits two features that are universally shared when daughter centrioles are formed: it associates with the vicinity of the proximal end of the mother centriole and its number is restricted to one.…”

“…The function of the daughter centriole is less clear. For example, in animal spermatids, the mother centriole, known as the distal centriole, becomes a basal body and gives rise to the sperm flagellum (Krioutchkova and Onishchenko 1999;Sathananthan et al 2001). The daughter centriole in spermatids, known as the proximal centriole, is attached to the nucleus.…”

Nuclear Segmentation, Condensation and Bilateral Symmetry in Polymorphonuclear Leukocytes Reflect Genomic Order and Favor Immunologic Function

“…Analysis of early embryogenesis revealed that the number of centrioles equals exactly the number of haploid sets of chromosomes in a cell [37] . (The second centriole of a spermatozoon is the originator and regulator of the flagellum, serving as tail, and is in no way connected to chromosomes or to the nuclear chromatin.)…”

Programming and Implementation of Age-Related Changes

“…Studies of spermatogenesis performed in insects (Sciara coprphila, Chrysopa carnea, Bombyx mori) and mammals (Heterohyrax syriacus and Memetes berdmorei) discovered that at the first meiotic division spindle poles contain a pair of centrioles, while at the second division e they contain only one centriole; in mammalians spermatocytes get two centrioles after both first and second divisions (Kriouchkova and nishchenco, 1999). On the contrary, oocytes of mammalians (mouse, rat, and rabbit) and Xenopus laevis do not have visible centriolar structures during both the meiotic divisions (Kriouchkova and Onishchenco, 1999). During the process of fertilization, the chromosomal sets of a spermatozoon and an oocyte are mixed.…”