Although our sample size is not

Although our sample size is not enough to conclude that there is no great genetic variation of the AR gene in most New World monkeys, it would be reasonable to state that the microsatellite region in the exon 1 of the androgen receptor gene of New World monkeys (platyrrhine) is relatively shorter than that in catarrhines. In addition, we observed that BS-181 HCl australia usage at the G repeat region in New World monkeys, especially in Callitrichidae, is unique among primates. GGA at the poly-G region is frequently used in tamarins and squirrel monkeys and used once in marmoset, capuchins, spider monkey and howler monkeys while the codon is never used in other taxa except for aye-aye (Fig. 2, Table 4). This suggests that the poly-G region has evolved uniquely in New World monkeys. The MDS analysis that shows the close relationship among New World monkeys supports this idea (Fig. 3). Uniqueness of New World monkeys in polymorphic regions of a functional gene comparing to Old World primates also has been reported in the serotonin transporter gene (Inoue-Murayama et al., 2008; Santangelo et al., 2016). The difference in androgen concentration between New World monkeys and Old World monkeys (Snipes et al., 1969) might be related to the regulation of androgen via AR. Thus, the relationship between sequence differences and functional differences of the AR gene among primates needs to be investigated in future research. It can be hypothesized that the length of poly-Q and poly-G regions should be balanced since AR works as a dimer, i.e. two identical molecules linked together (Li and Al-Azzawi, 2009). Although a negative correlation between poly-QI and poly-G lengths was observed in chimpanzees (Hong et al., 2006), no such relationship was observed in New World monkeys (Fig. 4). In humans, the combination between long Q and long G repeats seems associated with male infertility (Ferlin et al., 2004). These lines of evidence may suggest that the balancing between poly-Q and poly-G regions is important only when these repeats are too long as in the case of apes and humans. The nature of longer microsatellites in humans compared to other primates is one of the intriguing evolutionary questions. Although several mechanisms, such as differences in mutation ratio, reproductive age, population size etc. have been hypothesized (Rubinsztein et al., 1995), a clear explanation has not been put forward. The tendency of a short poly-Q region in New World monkeys shown in this study may provide new insight into the evolution of microsatellites in a functional gene in primates.
Introduction Despite the great advances in the field of assisted reproductive technologies (ART) in recent years, one of the fundamental steps to achieve success is still dependent on the number of eggs obtained after controlled ovarian stimulation (COS) [1,2]. Patients with low response to COS have been a challenge for ART and nowadays poor ovarian responders (POR) constitute 9–24% of all women undergoing COS [3]. The incidence is probably increasing because women are delaying motherhood and the average age at which women have access to ART is growing [4]. This fact becomes clinically relevant to predict the length of their fertile lifespan, which may be used during informed decision-making about timing of childbearing. The large variability in ovarian reserve in patients of the same age has prompted researchers to find a more reliable marker than chronological age to predict POR. Recently, new biomarkers, such as the serum concentration of anti-Müllerian hormone (AMH) and antral follicular count (AFC), have been suggested as valuable markers for predicting the ovarian reserve and the response to COS [5,6]. However, the variation of the AMH values during the life of women is not well known [7]. Thus genetics could be an option to predict the end of reproductive lifespan for a woman allowing to make decisions about family planning.