Rodrigo del Rio do Valle

Severe anemia affects both splenectomized and non-splenectomized Plasmodium falciparum-infected Aotus infulatus monkeys.

Severe anemia is the earliest and a frequently fatal complication of Plasmodium falciparum infection. Here we describe Aotus infulatus as a primate model suitable to study this malaria complication. Both non-splenectomized and splenectomized monkeys receiving different inocula of P. falciparum FVO strain presented large (> 50%) decreases in hematocrit values during infection. Non-splenectomized animals were able to control parasite growth (parasitemia did not exceed 4%), but they had to be treated because of severe anemia. Three of 4 splenectomized monkeys did not control parasitemia and were treated, but developed severe anemia after treatment when presenting a negative blood film. Destruction of parasitized red blood cells alone cannot account for the degree of anemia. Non-splenectomized monkeys repeatedly infected with homologous parasites became rapidly and progressively resistant to reinfection and to the development of severe anemia. The data presented here point to A. infulatus as a suitable model for studying the pathogenesis of severe malarial infection.

Sperm head morphometry in ejaculates of adult marmosets (Callithrix jacchus): a model for studying sperm subpopulations and among-donor variations.

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.

Epidermal growth factor effects on marmoset monkey (Callithrix jacchus) oocyte in vitro maturation, IVF and embryo development are altered by gonadotrophin concentration during oocyte maturation

BACKGROUND This is the first study of the effect of epidermal growth factor (EGF) on marmoset monkey oocytes matured in vitro. METHODS We have evaluated the effects of 10 ng/ml EGF in combination with 1 or 10 IU/ml of gonadotrophins (FSH/hCG 1:1 ratio) during in vitro maturation (IVM) of marmoset oocytes. Immature cumulus-oocyte complexes (COCs) were retrieved from ovarian antral follicles of unprimed monkeys. COCs from six animals (n= 268) used in this study were randomly distributed among four experimental groups: (A) 1 FSH +1 hCG; (B) 10 FSH +10 hCG; (C) 1 FSH +1 hCG + EGF; and (D) 10 FSH +10 hCG + EGF (where 1 and 10 are concentrations, IU/ml). After IVM, oocytes were fertilized in vitro and embryos were allowed to progress up to 87-88 h. RESULTS the highest rate of total and radial cumulus expansion was observed in Group A, with the lowest in Group B (P < 0.05). Neither maturation nor fertilization rate were affected by gonadotrophin concentration or presence of EGF. Addition of EGF increased degeneration and decreased first cleavage rate, which was significantly lower in Group C than Group A (P < 0.005). Interestingly, in the EGF groups some embryos cleaved faster than without EGF. CONCLUSIONS The effects of EGF are highly dependent on concentration of gonadotrophins present in IVM medium. EGF has a negative effect on oocytes in the presence of low gonadotrophins, but contrastingly partially protects oocytes from the negative effects of high gonadotrophins. We propose that these observed negative effects of EGF may suggest use of an inappropriate dose of growth factor.

Identification of sperm head subpopulations with defined pleiomorphic characteristics in ejaculates of captive Goeldi's monkeys (Callimico goeldii).

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 Goeldis 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.

Evaluation of the fecal steroid concentrations in Alouatta belzebul (Primates, Atelidae) in the National Forest of Tapirape-Aquiri in Pará, Brazil

The studies on fecal steroid metabolites published with free‐living primates are limited mainly by the difficulty in obtaining samples.

Sero-epidemiological survey for brucellosis, leptospirosis, and toxoplasmosis in free-ranging Alouatta caraya and Callithrix penicillata from São Paulo State, Brazil

Sera were tested for Brucella spp., Leptospira spp. and Toxoplasma gondii antibodies in 68 free‐ranging New World monkeys from a forest fragment of the Brazilian Cerrado.

Comparison of semen characteristics and sperm cryopreservation in common marmoset (Callithrix jacchus) and black-tufted-ear marmoset (Callithrix penicillata)

The common marmoset (Callithrix jacchus) is one of the most studied Neotropical primates regarding reproduction. However, little has been reported on the black‐tufted‐ear marmoset (Callithrix penicillata), which may produce fertile hybrids with other Callithrix. This is the first study to evaluate sperm freezing from black‐tufted‐ear marmoset.

Developmental and family history-based analysis of congenital fused labia phenotype in the captive common marmoset (Callithrix jacchus)

Congenital fused labia (CFL) is defined as a failure or significant delay in the opening of the juvenile sealed labia majora. This phenotype is known to be variably common in adult captive female marmosets but has never been investigated in detail before.