The ovarian cycles of four adult female spider monkeys (Ateles geoffroyi) were followed daily throughout 30 days by means of vaginal swabs and blood samplings. Cytological analyses of the vaginal swabs and radioimmunoassay determination of the daily levels of estradiol‐17β (E2) and progesterone (P4) were done in order to classify the kind of ovarian cycle of this species. Our results show that Ateles geoffroyi females display menstrual cycles of about 24 days on average. By comparison with the well‐known menstrual cycles of women, apes, and Old World monkeys, the four distinctive cytological phases (bleeding, follicular, periovulatory, and luteal) could be recognized; mid‐cycle E2 peaks followed by mid‐luteal increases of the same hormone were present in all four females. P4 levels were higher after the E2 peak, although both hormones were present throughout the cycles. Also, age‐dependent features, hormone profiles, and changes in menstrual phases lengths were detected. Am. J. Primatol. 44:183–195, 1998. © 1998 Wiley‐Liss, Inc.

The American Kennel Club and the Fédération Cynologique Internationale recognize two phenotypic variants of Great Dane breed denominated American and European varieties. Historically, these varieties have been segregated according to morphological characteristics. In an attempt to obtain a better characterization, breeders have been interested in the genetic parameters that could evaluate the within-breed diversity. In this document, we studied the genetic structure of Great Dane breed with 10 STR markers in 88 dogs using capillary electrophoresis. Cluster analysis, population differentiation and phylogenetic analyses revealed that American and European varieties are genetically independent. Nevertheless, within the American variety a genetic stratification was found. Additionally, a high misclassification (28%) was detected, which could be due to wrong registration or false paternity. Our results support the importance to deem genetic markers as useful tools in breeding control. Similarly, these studies serve as an accurate reference to establish standards by dog breeding associations and for choosing among dogs for inter-breeding. Nevertheless, genetic tools are only a complement of morphological methods, since both are reshuffling * These authors equally contributed to this work. # Corresponding author. G. Noris et al. 79the control over the breeding line. Notwithstanding, this database provides an overall and scape concerning the impact of genetic diversity within-breed. Unmistakably, more databases are needed to increase the quality of the breeding line as well as the number of STR in order to study, with more detail, the genetic structure in the Great Dane race.