ADELINA FERREIRA^1,* AND MAHMOUD MEHANNA²

BIOCELL, Vol.36, No.2, pp. 57-62, 2012, DOI:10.32604/biocell.2012.36.057

Abstract The reproductive cycle in anurans may be either continuous or discontinuous. These differences may be connected to seasonal climate changes and/or to anthropic activity. Forty adult male individuals of the Dendropsophus minutus species were collected during one year, in the municipality of Chapada dos Guimarães (Mato Grosso, Brazil). The testicles were studied under light and transmission electron microscopy. No variations were observed when the diameter of the seminiferous tubules and the thickness of the interstitial tissue were studied. However, changes in spermatogenesis were conspicuous and indicated that the reproductive cycle of D. minutus in Chapada dos Guimarães is discontinuous and… More >

GISELE ORLANDI INTROÍNI¹, FERNANDA MARTINS MAESTER¹, FOSCA Pedini PEREIRA LEITE² AND SHIRLEI MARIA RECCO-PIMENTEL¹

BIOCELL, Vol.34, No.3, pp. 103-112, 2010, DOI:10.32604/biocell.2010.34.103

Abstract Ultrastructural analyses of bivalve spermatozoa are relevant in studies that aim to identify taxonomic traits for the purposes of discriminating species and conducting phylogenetic studies. In the present work, spermatozoa of mussel specimens of the genus Mytella, collected from two populations living in distinct habitats, were examined by electron microscopy. The objective was to identify sperm ultrastructural taxonomic traits that could be used to differentiate Mytella species. The specimens were from populations that live in intertidal zones on the southeast coast of Brazil, either buried in muddy-sand sediment or anchored to rocky substrates. The acrosomal vesicle was conical and long,… More >

ADELINA FERREIRA¹, MAHMOUD MEHANNA^1,2, CYNTHIA P. A. PRADO³

BIOCELL, Vol.32, No.2, pp. 185-194, 2008, DOI:10.32604/biocell.2008.32.185

Abstract The spermatogenesis of Pseudis limellum, from the Southern Pantanal, Brazil, was studied from July 1995 to May 1996, through histological sections of the testis. The cells could be differentiated as: primary spermatogonia, large cells, generally with bilobed nucleus; secondary spermatogonia, smaller cells, with darker cytoplasm, chromatin of radial form; primary and secondary spermatocytes, differentiated according to the different stages of the nucleus during the successive cells divisions. Furthermore, we observed cells in process of morphologic differentiation: rounded spermatids much smaller, with nucleus containing chromatin in compacting process and cytoplasm reduction; elongated spermatids, generally parallel organized in well defined bundles, with… More >

H.R. CONTRERAS¹, V. PAREDES¹, B. URQUIETA², L. DEL VALLE⁴, E. BUSTOS-OBREGÓN³

BIOCELL, Vol.30, No.3, pp. 423-429, 2006, DOI:10.32604/biocell.2006.30.423

Abstract Parathion® is an organophosphorate pesticide amply used in agriculture. Many alterations induced by organophosphorate pesticides have been described, such as: cytogenetic alterations in germinal cells, oligozoospermia and teratozoospermia in the mouse. The effect of Parathion®, both pure (PP) and commercial (PC), on mouse interstitial cell testosterone production was evaluated in vivo and in vitro. Male mice were intraperitoneally injected with a single dose of 1/3 LD50 of Parathion®, both PP and PC. The animals were sacrificed at 1, 8 and 40 days post injection to evaluate the impact of disrupting testosterone production on spermatogonia, spermatocytes and elongated spermatids. The plasma… More >

P. CORNEJO*, E.L. CAMADRO**, R.W. MASUELLI*

BIOCELL, Vol.30, No.3, pp. 413-421, 2006, DOI:10.32604/biocell.2006.30.413

Abstract The Endosperm Balance Number (EBN) is an important concept for potato breeding and has evolutionary importance in tuber-bearing Solanum species. The EBN is part of the post-zygotic hybridization barriers in the group and represents a reproductive isolating mechanism. Few genes have been proposed to be involved in its genetic control; until now, however, neither specific genes nor its molecular basis have been well established. Histological observations of embryo and endosperm development in inter-EBN crosses in tuber-bearing Solanum revealed phenotypes similar to those recently described in Arabidopsis seed mutants. The common feature between them is that the endosperm nuclei become greatly… More >

SOON-JEONG JEONG¹, JOO-CHEOL PARK¹, HEUNG-JOONG KIM², CHUN SIK BAE³, MYUNG-HEE YOON⁴, DO-SEON LIM⁵, MOON-JIN JEONG¹

BIOCELL, Vol.30, No.2, pp. 279-286, 2006, DOI:10.32604/biocell.2006.30.279

Abstract This study examined the fine structures of epididymal spermatozoa on the lesser white-toothed shrew (Crocidura suaveolens), the Japanese white-toothed shrew (C. dsinezumi) and the big white-toothed shrew (C. lasiura) belonging to the subfamily Crocidurinae living in Korea.
In the spermatozoa of C. suaveolens, the head has a large acrosome, a smooth inner acrosomal membrane and a wavy, finger-like, electron-dense apical body. The neck has a solid proximal centriole that is filled with electron-dense material. These results showed the spermatozoa of C. suaveolens possess the characteristics of both Crocidurinae and Soricinae. In C. dsinezumi and C. lasiura, the head has… More >

LEONOR M.E. ITUARTE*, TERESA B. VIERA*, TEOBALDO A. SALDEÑA*, JUAN C. DE ROSAS**, MABEL FÓSCOLO**, JORGE E. IBÁÑEZ*, FERNANDO D. SARAVÍ*

BIOCELL, Vol.30, No.1, pp. 43-49, 2006, DOI:10.32604/biocell.2006.30.043

Abstract Electrophysiological events occur early after fertilization, along with changes in intracellular Ca²⁺ concentration . Passive electrical parameters were determined in golden hamster oocytes by whole cell patch-clamp method. In separate experiments the effect of 4-aminopyridine on resting oocytes was tested. The single-channel patch clamp configuration was employed to assess the electrical response to fertilization with homologous sperm. Structure of oocytes submitted to patch clamp was evaluated with scanning electron microscopy and found to be preserved.
Oocyte diameter was 70.2 ± 2.2 µm; their resting parameters were: membrane potential 23.8 ± 0.8 mV; total membrane specific resistance 519.1 ± 94.6… More >

MARIA CAROLINA AQUINO LUQUE, SÔNIA NAIR BÁO

BIOCELL, Vol.30, No.1, pp. 33-38, 2006, DOI:10.32604/biocell.2006.30.033

Abstract The ultrastructure of normal, ejaculated spermatozoa of Bos indicus was studied by means of electron microscopy, being evaluated in two principal parts, the head and the tail. The head is flat, oval or paddle-shaped with a square base, which provides a concave recess for the insertion of the tail. The acrosome tightly covers the anterior two thirds of the nucleus. A distinct unilateral acrosomal bulge was observed along the apical edge of the head. The equatorial region demarcates the acrosome from the post-equatorial region that covers the caudal one third of the nucleus. The classical 9+9+2 fiber pattern which composes… More >

ROBERTO YUNES, PEDRO FERNÁNDEZ, GUSTAVO F. DONCEL, ANÍBAL A. ACOSTA

BIOCELL, Vol.29, No.3, pp. 287-293, 2005, DOI:10.32604/biocell.2005.29.287

Abstract Our objective was to determine the effect of phosphodiesterase (PDE) inhibition on: 1) tyrosine phosphorylation of human spermatozoa at the tail level; and 2) sperm motion parameters and hyperactivated motility. The study was conducted with normozoospermic and asthenozoospermic samples incubated under in vitro capacitating conditions. The main outcome measures were computer-assisted sperm motion analysis and fluorescent immunodetection of phosphotyrosine-containing proteins. Pentoxifylline (PTX) was used as PDE inhibitor because of its wide use in the clinic. PTX-treatment significantly increased sperm velocity, hyperactivated motility and tyrosine-phosphorylation, both in normo and asthenozoospermic samples. Tyrosine-phosphorylation of tail proteins was highly conspicuous in both types… More >

CLAUDIA AGUILERA MERLO, ESTELA MUÑOZ, SUSANA DOMINGUEZ, MABEL FÓSCOLO*, LUIS SCARDAPANE, JUAN CARLOS DE ROSAS*

BIOCELL, Vol.29, No.3, pp. 243-251, 2005, DOI:10.32604/biocell.2005.29.243

Abstract Seasonal changes in the reproductive activity of the adult male viscacha (Lagostomus maximus maximus) were investigated during the annual reproductive cycle. Assays of heterologous in vitro binding between compatible gametes were used to evaluate the ability of viscacha spermatozoa to achieve primary binding during its annual reproductive cycle. Sperm were collected by mincing cauda epididymis in HECM-3 medium and the sperm concentration and motility were evaluated. Cumulus-free and zona-free oocytes obtained from superovulated hamsters were inseminated in vitro with capacitated sperm suspensions, incubated at 37ºC, 5% CO2 for 3 h, and then processed for studies by scanning electronic microscopy. Statistical… More >