Birth defects affecting the development of the reproductive tract have been frequently described in alpacas. In females these defects include underdeveloped genitalia, narrowed vaginal pass, abnormal uterus, enlarged clitoris and double cervix, while various types of ambiguities in internal and external genitalia are found in both males and females. All conditions are associated with impaired fertility or infertility. Though very little is known about the causes of these abnormalities, it is proposed that, like in other species, chromosome rearrangements count for some. The normal number of chromosomes for alpacas is 74. At the time of conception, the gender of the animal is determined on the basis of its sex chromosomes - XX for a female and XY for a male. Thus, sex chromosome abnormalities such as 73,XO (Turner’s syndrome) and 74, XX/XY (freemartin) result in abnormal sexual development and infertility. Birth defects and/or abnormal development of the female reproductive tract can be caused also be other chromosome abnormalities of which 74,XX-minute (Minute chromosome syndrome) is among the few known so far. This lack of knowledge is largely because alpacas (and other camelids) have high number of chromosomes and some of these, especially the smallest chromosomes, are very difficult to study. Therefore, the aim of this research proposal is to use traditional chromosome analysis methods in combination with new molecular tools to improve the characterization of chromosomal abnormalities that underlie impaired fertility in female and male alpacas.