Morphological characterization of cell death during the ovary differentiation in worker honey bee

Cell death that occurs during ovary differentiation in the honeybee worker's larval development accounts for ovariole reabsorption. From a morphological standpoint, three modes of death were detected. Germinative cells in the ovarioles die by an apoptotic-like process, whereas the somatic cells die by an autophagic process, type 11 cell death; and during pupation, stromatic and ovarian capsular cells die through cytoplasmic disintegration, releasing their components into the hemolymph. These modes of cell death are in part determined by the pattern of tissue organization within which the cell occurs. (C) 2002 Elsevier B.V. Ltd. All rights reserved.

Temporal and morphological differences in post-embryonic differentiation of the mushroom bodies in the brain of workers, queens, and drones of Apis mellifera (Hymenoptera, Apidae)

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

Mechanisms of karyotype differentiation in Cassidinae sensu lato (Coleoptera, Polyphaga, Chrysomelidae) based on seven species of the Brazilian fauna and an overview of the cytogenetic data

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Karyotype differentiation patterns in species of the subfamily Scarabaeinae (Scarabaeidae, Coleoptera)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Influence of the insecticide pyriproxyfen on the flight muscle differentiation of Apis mellifera (Hymenoptera, Apidae)

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

Chromosomal differentiation of populations of Lysapsus limellus limellus, L. l. bolivianus, and of Lysapsus caraya (Hylinae, Hylidae)

Cytogenetic analysis were done on specimens from two populations of Lysapsus limellus limellus. three of L. l. bolivianus and of one of Lysapsus caraya. All animals showed a diploid chromosomal number of 2n=24. The karyotypes of the two L. limellus subspecies were very similar, differing only by the larger amount of telomeric heterochromatin and a small pericentromeric C-band on the short arms of pair 2 in L. l. limellus specimens. The karyotype of L. caraya differed from those of the two L. limellus subspecies in terms of chromosomal morphology, C-banding pattern and location of the main NOR on chromosomes 7 and 6. respectively. The karyotype of the L. l. bolivianus population from Guajara-Mirim/RO differed from those of the other populations of the same subspecies in morphology and heterochromatin pattern of chromosomes 7 and 8. Additional NORs were detected by silver staining and confirmed by FISH in one of the homologues of pairs 1 and 8 in L. l. bolivianus and in pair 7 in L. caraya. These results suggest that a reassessment of the taxonomic status of L. limellus subspecies, especially of the L. l. bolivianus populations, may be necessary. (c) 2005 Elsevier Ltd. All rights reserved.

Molecular phylogeny and karyotype differentiation in Paratelmatobius and Scythrophrys (Anura, Leptodactylidae)

Paratelmatobius and Scythrophrys are leptodactylid frogs endemic to the Brazilian Atlantic forest and their close phylogenetic relationship was recently inferred in an analysis that included Paratelmatobius sp. and S. sawayae. To investigate the interspecific relationships among Paratelmatobius and Scythrophrys species, we analyzed a mitochondrial region (approximately 2.4 kb) that included the ribosomal genes 12S and 16S and the tRNAval in representatives of all known localities of these genera and in 54 other species. Maximum parsimony inferences were done using PAUP* and support for the clades was evaluated by bootstrapping. A cytogenetic analysis using Giemsa staining, C-banding and silver staining was also done for those populations of Paratelmatobius not included in previous cytogenetic studies of this genus in order to assess their karyotype differentiation. Our results suggested Paratelmatobius and Scythrophrys formed a clade strongly supported by bootstrapping, which corroborated their very close phylogenetic relationship. Among the Paratelmatobius species, two clades were identified and corroborated the groups P. mantiqueira and P. cardosoi previously proposed based on morphological characters. The karyotypes of Paratelmatobius sp. 2 and Paratelmatobius sp. 3 described here had diploid chromosome number 2n = 24 and showed many similarities with karyotypes of other Paratelmatobius representatives. The cytogenetic data and the phylogenetic analysis allowed the proposal/corroboration of several hypotheses for the karyotype differentiation within Paratelmatobius and Scythrophrys. Namely the telocentric pair No. 4 represented a synapomorphy of P. cardosoi and Paratelmatobius sp. 2, while chromosome pair No. 5 with interstitial C-bands could be interpreted as a synapomorphy of the P. cardosoi group. The NOR-bearing chromosome No. 10 in the karyotype of P. poecilogaster was considered homeologous to chromosome No. 10 in the karyotype of Scythrophrys sp., chromosome No. 9 in the karyotype of Paratelmatobius sp. 1, chromosome No. 8 in the karyotypes of Paratelmatobius sp. 2 and of Paratelmatobius sp. 3, and chromosome No. 7 in the karyotype of P. cardosoi. A hypothesis for the evolutionary divergence of these NOR-bearing chromosomes, which probably involved events like gain in heteochromatin, was proposed.

Overview of Caste Differentiation in the Polistinae, Emphasizing the Neotropical Swarm-Founding Polistinae (Hymenoptera, Vespidae, Epiponini)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Inhibition of 5-alpha-reductase activity induces stromal remodeling and smooth muscle de-differentiation in adult gerbil ventral prostate

Prostatic differentiation during embryogenesis and its further homeostatic state maintenance during adult life depend on androgens. Dihydrotestosterone, which is synthesized from testosterone by 5alpha-reductase (5alpha-r), is the active molecule triggering androgen action within the prostate. In the present work, we examined the effects of 5alpha-reductase inhibition by finasteride in the ventral prostate (VP) of the adult gerbil, employing histochemical and electron microscopy techniques to demonstrate the morphological and organizational changes of the organ. After 10 days of finasteride treatment at a dose of 100 mg/kg/day, the prostatic complex (VP and dorsolateral prostate) absolute weight was reduced to about 18%. The epithelial cells became short and cuboidal, with less secretory blebs and reduced acid phosphatase activity. The luminal sectional area diminished, suggestive of decreased secretory activity. The stromal/epithelial ratio increased, the stroma becoming thicker but less cellular. There was a striking accumulation of collagen fibrils, which was accompanied by an increase in deposits of amorphous granular material adjacent to the basal lamina and in the clefts between smooth muscle cells (SMC). Additionally, the periacinar smooth muscle became loosely packed. Some SMC were atrophic and showed a denser array of the cytoskeleton, whereas other SMC had a highly irregular outline with numerous spine-like projections. The present data indicate that 5alpha-r inhibition causes epithelial and stromal changes by affecting intra-prostatic hormone levels. These alterations are probably the result of an imbalance of the homeostatic interaction between the epithelium and the underlying stroma.

New molecular variants of hypothalamus-pituitary-gonad axis genes and their association with early puberty phenotype in Bos taurus indicus (Nellore)

Endocrine system plays a major role in the control of reproductive functions which are regulated by the hypothalamus-pituitary-gonad axis and its interactions. FSH and LH receptor genes are expressed at the gonads and GnRH receptor gene is expressed at the anterior pituitary gland. Misense mutations of the FSH, LH or GnRH receptors, activating or inactivating their functions in mammals, are potentially useful to allow the understanding of the role of this group of gonadotropins in reproductive phenotypes as early puberty and birth interval length. In the present study, polymorphisms in bovine exon 11 and 3'UTR of LHR, exon 10 and 3'UTR of FSHR and GnRHR genes were characterized with some of them resulting in changes in the aminoacidic chain. These polymorphic sites were found in a Bos taurus indicus (Nellore) female population by means of PCR-SSCP and DNA sequencing. Association between nucleotidic/aminoacidic changes and early puberty were determined by Chi-square analysis. It was found association between FSHR 3'UTR polymorphisms at position 2181, 2248 and 2249 bp and early puberty phenotype (p < 0.05). The presence of these new molecular markers might be considered in further studies to validate its correlation with early puberty or other reproduction associated phenotypes in cattle breeds. (C) 2007 Published by Elsevier B.V.

Differentiation of Leydig Cells in the Mongolian Gerbil

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

Neonatal Gonocyte Differentiation in Mongolian Gerbil Meriones unguiculatus Involves Asynchronous Maturation of Seminiferous Cords and Rapid Formation of Transitional Cell Stage

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

An adaptive view of caste differentiation in the neotropical wasp Polybia (Trichothorax) sericea Olivier (Hymenoptera: Vespidae)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Differentiation of Acidithiobacillus ferrooxidans and A-thiooxidans strains based on 16S-23S rDNA spacer polymorphism analysis

Restriction fragment length polymorphism (RFLP) and sequence analyses of the PCR-amplified 16S-23S rDNA intergenic spacer (ITS) were used for differentiating Acidithiobacillus thiooxidans strains from other related acidithiobacilli, including A. ferrooxidans and A. caldus. RFLP fingerprints obtained with AluI, DdeI, HaeIII, HinfI and MspI enabled the differentiation of all Acidithiobacillus reference strains into species groups. The A. thiooxidans strains investigated (metal mine isolates) yielded identical RFLP patterns to the A. thiooxidans type strain (ATCC 19377(T)), except for strain DAMS, which had a distinct pattern for all enzymes tested. Fourteen A. ferrooxidans mine strains were assigned to 3 RFLP groups, the majority of which were grouped with A. ferrooxidans ATCC 23270(T). The spacer region of one representative strain from each of the RFLP groups obtained was subjected to sequence analysis, in addition to eleven additional A. thiooxidans strains isolated from sediment and water samples, and A. caldus DSM 8584(T). The tRNA(IIe) and tRNA(Ala) genes, present in all strains analyzed, showed high sequence similarity. Phylogenetic analysis of the ITS sequences differentiated all three Acidithiobacillus species. Inter- and infraspecific genetic variations detected were mainly due to the size and sequence polymorphism of the ITS3 region. Mantel tests showed no significant correlation between ITS sequence similarity and the geographical origin of strains. The results showed that the 16S-23S rDNA spacer region is a useful target for the development of molecular-based methods aimed at the detection, rapid differentiation and identification of acidithiobacilli. (C) 2004 Elsevier SAS. All rights reserved.

CRANIOMETRIC VARIATION AND SUBSPECIFIC DIFFERENTIATION IN THRICHOMYS APEREOIDES IN NORTHEASTERN BRAZIL (RODENTIA, ECHIMYIDAE)

Thrichomys apereoides is an echimyid rodent which ranges in distribution from northeastern and central Brazil into Paraguay. Five subspecies are recognized, although each form is not well characterized and diagnosis is based primarily in pelage color variation. In this study we employed procedures from multivariate statistics to assess the systematic status of subspecies described from northeastern Brazil. The results of the craniometric analysis cannot be reconciled with the subspecies currently recognized for northeastern Brazil. Populations assigned to T. a. laurentius and T. a. inermis form a continuum of variation in cranial size, although they differ in cranial shape from a population from the locality of Bodoco in the state of Pernambuco. The implications of these findings for the systematics of T. apereoides are discussed.