Synteny of human chromosomes 14 and 15 in the platyrrhines (Primates, Platyrrhini)

In order to study the intra- and interspecific variability of the 14/15 association in Platyrrhini, we analyzed 15 species from 13 genera, including species that had not been described yet. The DNA libraries of human chromosomes 14 and 15 were hybridized to metaphases of Alouatta guariba clamitans, A. caraya, A. sara, Ateles paniscus chamek, Lagothrix lagothricha, Brachyteles arachnoides, Saguinus midas midas, Leontopithecus chrysomelas, Callimico goeldii, Callithrix sp., Cebus apella, Aotus nigriceps, Cacajao melanocephalus, Chiropotes satanas and Callicebus caligatus. The 14/15 hybridization pattern was present in 13 species, but not in Alouatta sara that showed a 14/15/14 pattern and Aotus nigriceps that showed a 15/14/15/14 pattern. In the majority of the species, the HSA 14 homologue retained synteny for the entire chromosome, whereas the HSA 15 homologue displayed fragmented segments. Within primates, the New World monkeys represent the taxon with the highest variability in chromosome number (2n = 16 to 62). The presence of the HSA 14/15 association in all species and subspecies studied herein confirms that this association is the ancestral condition for platyrrhines and that this association has been retained in most platyrrhines, despite the occurrence of extensive inter- and intrachromosomal rearrangements in this infraorder of Primates.

Tracking the Ovarian Cycle in Black-and-Gold Howlers (Alouatta caraya) by Measuring Fecal Steroids and Observing Vaginal Bleeding

A better understanding of a species` reproductive physiology can help conservation programs to manage primates in the wild and develop assisted reproductive technologies in captivity. We investigated whether measurements of fecal progestin and estrogen metabolites obtained by a radioimmunoassay could be used to monitor the ovarian cycle of Alouatta caraya. We also compared the occurrence of vaginal bleeding with the hormone profiles. We collected fecal samples from 3 adult and 1 subadult captive female over 5 mo and performed vaginal cytology for the adults. The interval between fecal progestin surges in the adult females was 19.11 +/- 2.14 d (n = 18 cycles). Fecal progestin concentrations remained at basal values for 9.83 +/- 2.21 d (n = 18) and rose to elevated values for 9.47 +/- 0.72 d (n = 19). The subadult female showed basal levels of fecal estrogen and progestin concentrations throughout the study, suggesting that our hormone measurements are valid to monitor the ovarian cycle. Bleeding periods coincided with basal levels of fecal estrogens and progestin at intervals of 19.8 +/- 0.9 d and lasted for 4.1 +/- 1.0 d. Although we obtained these data from only 3 individuals, the results indicate that this species likely has a menstrual-type ovarian cycle. These data provide the first endocrine profile for the Alouatta caraya ovarian cycle and are similar to results obtained for other howler species. This similarity is important for comparative studies of howlers, allowing for a better understanding of their reproductive physiology and contributing to a critical information base for managing Alouatta species.

The Y Chromosome of the Atelidae Family (Platyrrhini): Study by Chromosome Microdissection

In order to study the intergeneric variability of the Y chromosome, we describe the hybridization of the Y chromosome of Brachyteles arachnoides, obtained by microdissection, to metaphases of Ateles belzebuth marginatus, Lagothrix lagothricha, and Alouatta male specimens. Brachyteles arachnoides (Atelinae) has 62 chromosomes and a very small Y chromosome. Our results showed that the Brachyteles arachnoides Y chromosome probe hybridized to Lagothrix lagothricha metaphases yielding one hybridization signal on only the tiny Y chromosome, and when hybridized with Ateles belzebuth marginatus metaphases it yielded one hybridization signal on two thirds of the small acrocentric Y chromosome. However, no hybridization signal was observed in Alouatta metaphases (subfamily Alouattinae), a closely related genus in the Atelidae family. Furthermore, our data support a close phylogenetic relationship among Brachyteles, Ateles, and Lagothrix and their placement in the Atelinae subfamily, but exclude Alouatta from this group indicating its placement as basal to this group. Copyright (C) 2009 S. Karger AG, Basel