We are still exploring options for labs to collaborate with, or gain access to equipment, to perform the sex determination analysis on the fetal samples. Though the data gathered will still be useful without this information, the determination of fetal sex will enhance the data collected. Our original collaborator accepted another position at a university in a different state, and thus we are in search of another collaborator. We have to wait to perform this analysis until all other non-destructive data collection is complete, as this analysis requires removing a portion of the fetal tail.

We conducted a proof-of-concept microCT scan of the E18 fetal chest area to garner what soft tissue information we could observe without any staining, and to determine the best settings for getting bone data for these samples using our microcomputed tomography (microCT) machine. During ASGSR, we began developing an additional collaboration to increase the data that could be gathered with the microCT scanning of the fetal samples. The scanner available to a potential collaborator can have an attenuator sheet placed between the sample and the beam, which would enable scanning of bones and soft tissue without needing to stain the samples or perform any other destructive measurements. This is not possible with the core equipment available at the Principal Investigator's (PI’s) institution. We are in the process of preparing a few E18 and E12 samples to send to our new collaborator for a test scan before sending all of the samples in batches.

MicroCT scanning of the maternal tibia (AIM 1) has been completed at the proximal metaphyseal area and midshaft. Our team is actively working on analyses of the scans. A few bones may need to be rescanned, which currently prevents us from shipping the samples to the Co-Investigator (Co-I) for mechanical testing. MicroCT scans of the femur remain to be completed, but time on the microCT machine is currently at a premium. Due to the potential need to rescan samples, we have nothing to report regarding the mechanical testing planned.

Plastic embedding of the samples and the re-embedding is complete. Training of a new student is underway to complete the histologic sectioning. As the samples are from a mouse, we are being very careful to ensure that no sample is lost due to lack of training. Samples for paraffin embedding have been decalcified and will be taken to the histology core for embedding in May 2024. After embedding in paraffin, we will begin the immunohistochemical and marrow adipose staining and analyses.