Sara Carioscia studies how genetics can contribute to bias and dispersion in early human cell divisions. Only approximately half of human conceptions survive to birth. The leading cause of pregnancy loss is aneuploidy – extra or missing chromosomes, most commonly occurring due to cell division errors in female meiosis. During meiosis, a single cell splits twice, producing four haploid cells, each with one copy of each chromosome. Female meiosis, which begins during fetal development, is particularly error-prone, and this error rate increases with maternal age.

Crossovers between chromosomes are crucial for ensuring faithful segregation of chromosomes. Although it has long been known that abnormal meiotic crossover recombination confers risk of aneuploidy, limited data have precluded a more complete understanding of the links between crossovers, aneuploidy, and their shared genetic basis. To address this gap, Sara’s project has performed retrospective analysis of preimplantation genetic testing data from in vitro fertilized embryos. In repurposing these clinical data, Sara seeks to understand the distribution of these traits and their potential genetic contributors.

Prior to enrolling at Johns Hopkins University and CMBD, Sara worked as a government contractor for the executive branch, completing science policy projects for agencies including the NIH and NASA. She visited a number of graduate programs and ultimately chose to join the CMDB program because of the supportive nature of the individuals in the program as well as the breadth of the work and expertise. The core graduate courses – Cell, Molecular, Developmental Biology, and Biophysics, as well as the week-long computational biology bootcamp and full-year lab course – were particularly enticing in the application process. But upon interviewing, she was particularly struck by the collaborative and supportive nature of the other students in the program. They showed genuine interest in one another’s work and went a long way to establish a collegial and friendly community. She visited again outside of the formal interview weekend, attending classes, grabbing lunch with the first-year students, and making the decision to join CMDB an easy one.

Beyond CMDB, the university also offers infrastructure and resources for further training and for extracurriculars. Sara has designed two courses for undergraduates, focused on computational biology and evolution. She has also appreciated the numerous opportunities to practice presentation and public speaking, both within the department (e.g., through first-year rotation talks and annual progress report presentations) as well as through joint seminars and meetings with groups across the university. Outside the lab, she competes with the Hopkins Cycling Team and participates in bike races around the region.

The McCoy lab is a supportive and interested group. “I always leave my meetings with my PI feeling encouraged and focused. We can talk about the big picture, exciting directions for the project, as well as details about the process and next analyses. And my labmates are my first sounding board and my final editors. I appreciate and look forward to their insights and inputs every time.”