Cytological steps during spermiogenesis in the house sparrow (Passes domesticus, Linnaeus)

Spermiogenesis of the domestic sparrow was investigated with the light and electron microscopes and a step by step classification is proposed. Three cell populations corresponding to early, mid and late spermatids were easily divided according to their positions in the seminiferous epithelium. In addition to this initial separation, six steps were recognized, based on nuclear morphology and the degree of chromatin condensation, in association to their acrosomal and flagellar development. Early spermiogenesis is the period previous to chromatin condensation. The first step can be recognized by the extending flagellum and the second by the pro-acrosome development in contact with the nucleus. During the third or intermediate step, chromatin condenses and the cell becomes polarized with the pro-acrosomic vesicle and the tail occupying opposite sides of the nucleus. Late spermiogenesis, including steps IV-VI, is marked by complete chromatin condensation. The final cellular modifications lead to the formation of a spiraled spermatozoon. This shape is due to the twisting of the acrosome and nucleus, as well as the helical arrangement of mitochondria around the axoneme along most of the flagellum, making an exceptionally long middle piece. (C) 2002 Elsevier B.V. Ltd. All rights reserved.

Morphometry and histochemistry of the semitendinosus muscle of tufted capuchin monkeys (Cebus apella Linnaeus, 1758)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Níveis séricos de cortisol e 17-& estradiol durante o ciclo estral em marrãs (Sus domestica - Linnaeus 1758)

In the present study 21 young swine females, sexually mature, reared and kept under an industrial management system were assessed for cortisol and oestradiol-17 beta serum prolifes during the oestrus cycle. Blood sampling was performed always at the same interval, from 8:00 to 10:00 a.m. Each animal was submitted to 14 venal punctions at days 0, 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 21, 22 and 23 of the oestrous cycle. The first day of the oestrous phase was assumed to be day 0 and the 23(rd) as the first of the next cycle. Hormone determinations were performed using a solid phase radioimmunoassay (RIA). Regarding to cortisol concentrations, there was a variation from 3.5 to 8.0 mu g/dl and for oestradiol-17 beta the mean values detected varied from 3.5 to 14.9pg/ml.

Anatomoradiographic description of the teeth of pacas bred in captivity (Agouti paca, Linnaeus, 1766)

Two newborn males, two adult males 9 and 72 months old, one newborn female and two adult females of 30 and 54 months old pacas were used. Animals were radiographed on lateral recumbency, teeth were extracted and the vestibulolingual and mesiodistal lengths were achieved at the occlusal surface, besides the longitudinal length. The lower incisors presented greater length in relation to the other ones and sinuous shape; the upper incisors, relatively smaller, are practically straight. There is no canine tooth, and after a great diastema there is one premolar and three molars in each hemiarcade. In adult pacas, the enamel of incisors presents yellowish colour, mainly in the labial surface; in the premolars and molars, the enamel is present as internal sheets disposed nearly in a parallel way and in vestibulolingual direction, through practically all the dental length, which provides several joined teeth aspect.

Microscopic characterization of teeth of pacas bred in captivity (Agouti paca, Linnaeus, 1766)

The microscopic description of the teeth of pacas (Agouti paca) bred in captivity was developed for providing biological data on one of the largest American wild rodents, as not many references exist in the literature about this species. Two newborn males, two adult males (9 and 72 months old), one newborn female and two adult females (30 and 54 months old) were used after death due to fights, neonatal cannibalism or unknown causes. Animals were radiographed, and their teeth were extracted and put on an acrylic resin block, cut on a diamond-like disc microtome and diaphanized. It was noted that enamel surrounds the coronary dentine and projects to the root region, besides being present as internal laminae, arranged in a parallel way and in the vestibulolingual direction. The dentine is located between the enamel laminae and surrounds the pulp horns. The cementum is located internal to the enamel laminae. From scanning electronic microscopy, we find that the enamel is the outer element on the vestibular surface, and it is in direct contact with the dentine. on the lingual surface, the cementum and dentine are the outer elements.

Crystallization, preliminary X-ray analysis and molecular-replacement solution of the carboxy form of haemoglobin I from the fish Brycon cephalus

Haemoglobin, the 'honorary enzyme' [Brunori (1999), Trends Biochem. Sci. 24, 158-161], constitutes a prime prototype for allosteric models. Here, the crystallization and preliminary X-ray analysis of haemoglobin I from the South American fish Brycon cephalus are reported. X-ray diffraction data have been collected to 2.5 Angstrom resolution using synchrotron radiation (LNLS). Crystals were determined to belong to the space group P6(1)22 and preliminary structural analysis revealed the presence of one dimer (alpha beta) in the asymmetric unit. The structure was determined using standard molecular-replacement techniques.

Storaged products and presence of acid phosphatase in fat body cells at pre-pupal worker stage of Apis mellifera Linnaeus, 1758 (Hymenoptera, Apidae)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Biological aspects of Orius insidiosus (Say) feeding on eggs of Plutella xylostella (Linnaeus) and Anagasta kuehniella (Zeller).

The objective of this work was to evaluate the biology of Orius insidiosus fed on eggs of Plutella xylostella and Anagasta kuehniella. The eggs used were obtained from the Laboratorio de Biologia e Criacao de Insetos, Departamento de Fitossanidade, FCAV/UNESP. The experiment was carried out with a total of 50 12-to-24-hour-old O. insidiosus nymphs, 1 per Petri dish (50 replications). P. xylostella or A. kuehniella eggs were places into each Petri dish daily, along with a small cotton pad moistened with distilled water. The evaluations were carried out daily. The adults were separated in couples, and placed in Petri dishes. The following biological aspects were evaluated: duration, survival rate and consumption of the nymph instars and of the nymph period; longevity of males and females; consumption per day and adult longevity; eggs per day; female fecundity; egg viability; embryonic period; preoviposition period, oviposition period, post-oviposition period. The fertility life table parameters were also evaluated. The predator O. insidiosus did not present significant differences for its biological characteristics, when feeding on P. xylostella and A. kuehniella eggs, however it showed improved fertility life table parameters when fedo n eggs of P. xylostella, suggesting the possibility of using these eggs in the mass rearing of this insect.

Effects of environmental colour on growth of Nile tilapia, Oreochromis niloticus (Linnaeus, 1758), maintained individually or in groups

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Estrutura, ultraestrutura e morfometria da aorta de paca (Cuniculus paca, Linnaeus, 1766) criada em cativeiro

The aim of this study was to describe the morphology, morphometry and ultrastructure of segments of thoracic and abdominal aorta portions in four male and female paca (Cuniculus paca). Parts of the segments were examined by light microscopy and part by scanning electron microscopy. Thickness measurements of the tunica intima and media complex and tunica adventitia of the aorta were taken. In all animals the thickness values for the tunica intima and media complex of the cranial thoracic aorta were significantly higher (mean: 702.19 mu m) when compared to the values of other aortic segments analyzed (means: 354.18 mu m; 243.55 mu m). The layers of the vessel walls show variations in structure and thickness, presumably due to an adaptation to functionaldemand.