RESUMO

The recessive lethal character Luteus-Pa is found in cacao (Theobroma cacao) genotypes of the Parinari series (Pa) and is characterized by expression of leaf chlorosis and seedling death. Several genotypes of the Pa series are bearers of the gene responsible for the expression of the Luteus-Pa character, which can be used as a tool for determining relationships between genotypes of this group. To evaluate this phenomenon, we analyzed the differential expression of genes between mutant seedlings and wild-type hybrid Pa 30 x 169 seedlings, with the aim of elucidating the possible lethal mechanisms of the homozygous recessive character Luteus-Pa. Plant material was harvested from leaves of wild and mutant seedlings at different periods to construct a subtractive library and perform quantitative analysis using real-time PCR. The 649 sequences obtained from the subtractive library had an average length of 500 bp, forming 409 contigs. The probable proteins encoded were grouped into 10 functional categories. Data from ESTs identified genes associated with Rubisco, peroxidases, and other proteins and enzymes related to carbon assimilation, respiration, and photosystem 2. Mutant seedlings were characterized by synthesizing defective PsbO and PsbA proteins, which were overexpressed from 15 to 20 days after seedling emergence.

Assuntos

RESUMO

The black-and-gold howler monkey serves as a suitable model for development of assisted reproductive techniques (ARTs), which may later be applied in threatened species of the same genus. The objectives of this study were to evaluate semen characteristics of black-and-gold howler monkeys (Alouatta caraya), with emphasis on mitochondrial activity and acrosome integrity, using staining methods that are suitable for use under field conditions. Twenty six semen samples were collected by rectal probe electroejaculation from six adult captive males from the National Primate Center (CENP), Ananindeua, PA, Brazil. The following parameters were evaluated in each semen sample: volume, pH, concentration, plasma membrane integrity, acrosome integrity, and mitochondrial activity. Both Spermac stain and the Simple Staining Method were suitable for acrosome evaluation. Diaminobenzidine needs further investigation to improve its application for this species. Overall semen quality improved from the first collection to the fifth collection. This highlights the importance of repeating semen collections when evaluating a male for use in ARTs. This research brought novel information on semen characteristics of Alouatta caraya which will aid further studies on the application of ARTs in this and other primate species.(AU)

Assuntos

RESUMO

The black-and-gold howler monkey serves as a suitable model for development of assisted reproductive techniques (ARTs), which may later be applied in threatened species of the same genus. The objectives of this study were to evaluate semen characteristics of black-and-gold howler monkeys (Alouatta caraya), with emphasis on mitochondrial activity and acrosome integrity, using staining methods that are suitable for use under field conditions. Twenty six semen samples were collected by rectal probe electroejaculation from six adult captive males from the National Primate Center (CENP), Ananindeua, PA, Brazil. The following parameters were evaluated in each semen sample: volume, pH, concentration, plasma membrane integrity, acrosome integrity, and mitochondrial activity. Both Spermac stain and the Simple Staining Method were suitable for acrosome evaluation. Diaminobenzidine needs further investigation to improve its application for this species. Overall semen quality improved from the first collection to the fifth collection. This highlights the importance of repeating semen collections when evaluating a male for use in ARTs. This research brought novel information on semen characteristics of Alouatta caraya which will aid further studies on the application of ARTs in this and other primate species.

Assuntos

RESUMO

The aim of this study was to develop an objective method to determine the incidence of pleiomorphisms and its influence on the distribution of sperm morphometric subpopulations in ejaculates of howling monkeys (Alouatta caraya) by using a combination of computerized analysis system (ASMA) and principal component analysis (PCA) methods. Ejaculates were collected by electroejaculation methods on a regular basis from five individuals maintained under identical captive environmental, nutritional, and management conditions. Each sperm head was measured for dimensional parameters (Area [A, (square micrometers)], Perimeter [P, (micrometers)], Length [L, (micrometers)], and Width [W, (micrometers)]) and shape-derived parameters (Ellipticity [(L/W)], Elongation [(L - W)/(L + W)], and Rugosity [(4лA/P (2))]). PCA revealed two principal components explaining more than the 96 % of the variance. Clustering methods and discriminant analyzes were performed and seven separate subpopulations were identified. There were differences (P < 0.001) in the distribution of the seven subpopulations as well as in the incidence of abnormal pleiomorphisms (58.6 %, 49.8 %, 35.1 %, 66.4 %, and 55.1 %, P < 0.05) among the five donors tested. Our results indicated that differences among individuals related to the incidence of pleiomorphisms, and sperm subpopulational structure was not related to the captivity conditions or the sperm collection method, since all individuals were studied under identical conditions. In conclusion, the combination of ASMA and PCA is a useful clinical diagnostic resource for detecting deficiencies in sperm morphology and sperm subpopulations in A. caraya ejaculates that could be used in ex situ conservation programs of threatened species in Alouatta genus or even other endangered neotropical primate species.

Assuntos

RESUMO

The performances of the diluents TES and CEBRAN II were compared as cryopreservatives of semen from non human primates of the genus Ateles. The experiment was carried out using one Ateles marginatus and two Ateles paniscus specimens, males and adults, maintained in the same captivity conditions at the National Center of Primates (CENP-SVS/MS). The animals were subjected to clinical and andrological examinations - testicular biometry - before the semen collection by eletroejaculation. Evaluations of motility and forward movement in the fresh semen were made. Semen were made dilution was made with the diluents TES and CEBRAN II. The ejaculates were diluted with the diluents (2:1proportion), packed in 0.25mL plastic straws and cryopreserved in liquid nitrogen. After thawing, the packed ejaculates were appraised in thermo resistance test (TTR). The averages of volume and concentration were, respectively, 1.94mL (0.83) and 3,020,000 sptz/mL (275.97). The pH 8 and seminal coagulation were observed in all samples. The results suggest that the TES diluent presents better efficiency in the preservation of Ateles semen than CEBRAN II.

Assuntos

RESUMO

The performances of the diluents TES and CEBRAN II were compared as cryopreservatives of semen from non human primates of the genus Ateles. The experiment was carried out using one Ateles marginatus and two Ateles paniscus specimens, males and adults, maintained in the same captivity conditions at the National Center of Primates (CENP-SVS/MS). The animals were subjected to clinical and andrological examinations - testicular biometry - before the semen collection by eletroejaculation. Evaluations of motility and forward movement in the fresh semen were made. Semen were made dilution was made with the diluents TES and CEBRAN II. The ejaculates were diluted with the diluents (2:1proportion), packed in 0.25mL plastic straws and cryopreserved in liquid nitrogen. After thawing, the packed ejaculates were appraised in thermo resistance test (TTR). The averages of volume and concentration were, respectively, 1.94mL (0.83) and 3,020,000 sptz/mL (275.97). The pH 8 and seminal coagulation were observed in all samples. The results suggest that the TES diluent presents better efficiency in the preservation of Ateles semen than CEBRAN II.(AU)

Assuntos

RESUMO

The aim of this study was to evaluate the incidence of pleiomorphisms and its influence on the distribution of sperm morphometric subpopulations in ejaculates from the vulnerable Goeldi's monkey (Callimico goeldii) by using a combination of computerized analysis system and Principal Component Analysis (PCA) methods. Each sperm head was measured for four primary spermatozoal head dimensional parameters (area [A (µm(2))], perimeter [P (µm)], length [L (µm)] and width [W (µm)]) and three head shape derived parameters (ellipticity [(L/W)], elongation [(L-W)/(L+W)] and rugosity [(4πA/P(2))]). Six separate subpopulations (SPs) were identified: SP1, constituted by very large, narrow and very elliptical spermatozoa (A=16.85±1.56µm(2), W=2.75±0.42µm and ellipticity=2.16±0.24); SP2, characterized by average sized, short, wide and round spermatozoa (A=15.00±1.92µm(2), L=5.06±0.49µm, W=3.51±0.31µm and ellipticity=1.44±0.15); SP3, represented by small, wide and slightly round spermatozoa (A=14.95±1.75µm(2), W=3.47±0.29µm and ellipticity=1.48±0.14); SP4 included very small, short and very round spermatozoa (A=14.15±2.38µm(2), L=4.90±0.57µm and elongation=0.18±0.05); SP5 consisted of average sized and slightly elliptical spermatozoa (A=15.14±1.72µm(2) and ellipticity=1.49±0.14); and SP6 included large and round spermatozoa (A=16.30±1.62µm(2) and elongation=0.19±0.04). There were differences in the sperm subpopulation distribution (P<0.001) among the five donors analyzed. In conclusion, the results of the current study confirmed that the use of computer sperm analysis methods combined with PCA cluster analyses are useful methods to identify, classify, and characterize different sperm head morphometric subpopulations in neotropical primates. Broadening our knowledge of C. goeldii sperm morphometric abnormalities as well as developing reliable techniques for sperm evaluation may be essential for ex situ conservation of this threatened species.

Assuntos

RESUMO

In humans and other mammals, sperm morphology has been considered one of the most important predictive parameters of fertility. The objective was to determine the presence and distribution of sperm head morphometric subpopulations in a nonhuman primate model (Callithrix jacchus), using an objective computer analysis system and principal component analysis (PCA) methods to establish the relationship between the subpopulation distribution observed and among-donor variation. The PCA method revealed a stable number of principal components in all donors studied, that represented more than 85% of the cumulative variance in all cases. After cluster analysis, a variable number (from three to seven) sperm morphometric subpopulations were identified with defined sperm dimensions and shapes. There were differences in the distribution of the sperm morphometric subpopulations (P < 0.001) in all ejaculates among the four donors analyzed. In conclusion, in this study, computerized sperm analysis methods combined with PCA cluster analyses were useful to identify, classify, and characterize various head sperm morphometric subpopulations in nonhuman primates, yielding considerable biological information. In addition, because all individuals were kept in the same conditions, differences in the distribution of these subpopulations were not attributed to external or management factors. Finally, the substantial information derived from subpopulation analyses provided new and relevant biological knowledge which may have a practical use for future studies in human and nonhuman primate ejaculates, including identifying individuals more suitable for assisted reproductive technologies.

Assuntos

RESUMO

The lethal gene 'Luteus-Pa' is found in cacao genotypes (Theobroma cacao) of the Parinari (Pa) series, from Peru. Seedlings affected by this gene have yellowing leaves and subsequently die. We mapped this gene based on microsatellite markers and RAPDs, in order to elucidate the inheritance of 'Luteus-Pa' and investigate possible lethal mechanisms. DNA samples of genitors were amplified with 87 SSR and 64 RAPD primers. The SSR primers amplified 65 RAPD primers, giving 179 polymorphic bands. After screening with SSR and RAPD markers, we selected 20 SSR primers, two SSR primers with ESTs and 22 RAPD primers that were polymorphic for genitors Pa 30 and Pa 169. Only two of the 22 RAPD primers and three of the 20 SSR primers were informative and polymorphic in the analysis of the bulk samples of progenies. Among these, primer RAPD E11 produced a band linked to the lethal gene (38.5 cM); none of the SSRs were associated with 'Luteus-Pa'.

Assuntos

RESUMO

The genome sequence of the hemibiotrophic fungus Moniliophthora perniciosa revealed genes possibly participating in the RNAi machinery. Therefore, studies were performed in order to investigate the efficiency of gene silencing by dsRNA. We showed that the reporter gfp gene stably introduced into the fungus genome can be silenced by transfection of in vitro synthesized gfpdsRNA. In addition, successful dsRNA-induced silencing of endogenous genes coding for hydrophobins and a peroxiredoxin were also achieved. All genes showed a silencing efficiency ranging from 18% to 98% when compared to controls even 28d after dsRNA treatment, suggesting systemic silencing. Reduction of GFP fluorescence, peroxidase activity levels and survival responses to H(2)O(2) were consistent with the reduction of GFP and peroxidase mRNA levels, respectively. dsRNA transformation of M. perniciosa is shown here to efficiently promote genetic knockdown and can thus be used to assess gene function in this pathogen.

Assuntos

RESUMO

Semen samples (n=58) were collected by electroejaculation from nine adult male howler monkeys (Alouatta caraya) between November 2000 and August 2001 at the National Primates Center, Ananindeua, Brazil. The ejaculates were free of coagulum. Mean (+/-S.D.) values were: volume, 0.09 +/- 0.05 ml; pH, 8.1 +/- 0.5; concentration 649.5 +/- 926.7 x 10(6) sperm/ml; progressive motility, 75.8 +/- 18.1%; forward progressive sperm motility (scale, 0-5), 3.5 +/- 1.0; live spermatozoa, 68.3 +/- 15.0%; primary defects, 9.6 +/- 4.5%; and secondary defects, 11.8 +/- 4.6%. There were high correlations between motility and live sperm (r = 0.91, P < 0.01), motility and forward progressive sperm motility (r = 0.84, P < 0.01) and between forward progressive sperm motility and live sperm (r = 0.78, P < 0.01). There were no alterations observed during clinical examinations and hematological analysis performed before and after semen collection. Therefore, the method was considered safe and efficient. It can be used for the evaluation of the breeding potential of male howler monkeys in captivity and for the establishment of new assisted reproductive technology (ART) for threatened species of neotropical primates.

Assuntos

RESUMO

Groups of 14-year-old cacao (Theobroma cacao L.) trees were hand pollinated, pollinated naturally or had their fruits continuously removed. Wilted and non-wilted cherelles (small fruits) were counted every 2 weeks, fallen flowers were counted weekly and mature pods were harvested monthly from 1983 through 1986. Carbohydrate, lipid and protein contents of wilted cherelles, mature pods and flowers were determined. Continuous removal of fruits caused a constant initiation of flowers and a significant increase in flowering intensity compared with the other treatments. The quantity of cherelles in the hand-pollinated trees was significantly greater than in the naturally pollinated trees. However, the number of mature fruits in both treatments was not statistically different because of increased cherelle wilting in the hand-pollinated trees. The continuously depodded trees allocated approximately 8 and 5 times more assimilate to flower production than the hand- and naturally pollinated trees, respectively. The naturally pollinated trees used only about one third as much energy for the production of flowers and wilted cherelles as the hand-pollinated trees, but about 1.4 times more energy than the depodded trees. It is concluded that fruit set in cacao is regulated by assimilate production and that cherelle wilting is the mechanism whereby the tree adjusts production.