A transmission electron microscopy investigation: the membrane complex in spermatogenesis of Fenneropenaeus chinensis

Abstract

The transforming characteristics of the membrane complex in spermatogenesis of Fenneropenaeus chinensis have been studied by using transmission electron microscopy. Two types of membrane complex have been investigated based on their sources: one originating from nucleus and the other from cytoplasm. The first one, consisted of annular structures, monolayer membrane blebs, and double or multi-lamellar membrane vesicles, emerges in the primary spermatocyte, then diffuses with the nuclear membrane and finally enters the cytoplasm. This type of membrane complex seems to play an important role in the materials transfusion from nucleus to cytoplasm, and it mainly exists inside the primary spermatocyte with some inside the secondary spermatocyte. The latter, originated from cytoplasm, is formed during the anaphase of spermiogenesis. It also exists in mature sperm, locating at both sides of the nucleus under the acrosomal cap. This type of membrane complex mainly comprises rings of convoluted membrane pouches, together with mitochondria, annular lamina bodies, fragments of endoplasmic reticulum, nuclear membrane and some nuclear particles. It releases vesicles and particles into the acrosomal area during the formation of the perforatorium, suggesting a combined function of the endoplasmic reticulum, mitochondria and Golgi's mechanism.

Transition of basic protein during spermatogenesis of Fenneropenaeus chinensis (Osbeck, 1765)

“…Using TEM to study the ultra-fine structure of the male germ cell of F. chinensis during spermatogenesis, we have found, in the early spermatogenesis (spermatogonia, primary spermatocytes, and secondary spermatocyte), that the cellular stages and their morphological characteristics are not different from those of other invertebrates and vertebrates, except for the membrane vesicle and annular structure in the nucleus, which we have described before (Kang et al 2008). The cellular differentiation before and during the meiotic process is quite conserved (Roosen 1969;Sobhon et al 2001;Manochantr et al 2003).…”

“…The prominent nucleolus and the synaptonemal complexes can be seen. Membrane vesicles and annular structure as we have described before (Kang et al 2008) are present in the nucleus. The cytoplasm contains abundant ribosomes with which most cohered to the endocytoplasmic reticulum, some mitochondria, as well as rare Golgi complexes (Fig.…”

“…Membrane vesicles in the nucleus play an essential role in materials transportation from the nucleus to the cytoplasm (Kang et al 2008). No labeling in the nuclear membrane vesicle (Fig.…”

“…Based on our observation of the development of acrosome during spermiogenesis (Ge et al 2008a, b) and the membrane complex in spermatogenesis of F. chinensis (Kang et al 2008), we classify its spermatogenesis into spermatogonia, primary spermatocyte, secondary spermatocyte, four stages of spermatid, and mature sperm, according to the ultrastructural characteristics of the developing male germ cells. We observe the histone transition during its spermatogenesis with transmission electron microscopy (TEM) of ammoniacal silver reaction (ASR) and further study the immunoelectron microscopical distribution of acetylated histone H4 during its spermatogenesis, trying to present the transition characteristics of basic protein during spermatogenesis of F. chinensis and attempt to correlate these findings with the noncondensed sperm nucleus.…”

Descripción histológica de la oogénesis y espermatogénesis del camarón de cultivo, Litopenaeus vannamei

“…Sin embargo, los estudios de Medina (1994), Abraham et al (2007) y Kang et al (2008) refieren el desarrollo de espermatozoides con espinas completas en los túbulos del testículo de P. longirostris, M. monoceros y Fenneropenaeus chinensis (Osbeck, 1765), respectivamente. Las observaciones del presente estudio para L. vannamei, claramente indican que las espermátidas que salen del testículo están inmaduras y continúan su desarrollo en los ductos deferentes, completando la formación de la cápsula acrosomal y la espina, de manera similar a la maduración de espermátidas de L. setiferus (King 1948) y Sicyonia ingentis (Sicyoniidae, Shigekawa & Clark 1986).…”