Biology subjects

Alleyne, K.

Publications and source records attributed to Alleyne, K..

2 recordsLinked to original sources

bioRxiv2022

The effects of ethnoracial-related stressors during pregnancy on the developing offspring brain.

We are increasingly aware of the effects of ethnoracial stress on health, with emerging interest in the potential for intergenerational transmission before birth. Here, we investigate the effect of maternal prenatal discrimination and acculturation experiences on fetal growth, birth outcomes, and functional connectivity in the infant brain. In pregnant adolescent women, we collected self-report measures of acculturation (tailored to an adolescent and Latinx population), discrimination, and maternal distress (i.e., stress and depressive symptoms; n=165). Fetal growth were obtained via electronic health records (n=92), and infant amygdala seed connectivity was assessed using functional magnetic resonance imaging (n=38). We found that greater maternal prenatal assimilation to the host culture was associated with slower fetal growth, lower gestational age at birth, and weaker amygdala-fusiform connectivity. Maternal prenatal discrimination was associated with weaker amygdala-prefrontal connectivity. Together, these results suggest intergenerational effects of ethnoracial stressors on the growth and neural development of future generations.

neuroscience↗

bioRxiv2021

Unique features of magic spot metabolism in Clostridioides difficile

The magic spot alarmones (pp)pGpp, previously implicated in Clostridioides difficile antibiotic survival, are synthesized by CdRSH and CdRelQ. These enzymes are transcriptionally activated by diverse environmental stresses, but both exclusively synthesize pGpp rather than ppGpp as has previously been reported. While direct synthesis of pGpp from a GMP substrate and (p)ppGpp hydrolysis into pGpp by NUDIX hydrolases have previously been reported, there is no precedent for a bacterium synthesizing pGpp exclusively. Hydrolysis of the 5 phosphate or pyrophosphate from GDP or GTP substrates is necessary for activity by the clostridial enzymes, neither of which can utilize GMP as a substrate. Both enzymes are remarkably insensitive to the size of their metal ion cofactor, tolerating a broad array of metals that do not allow activity in (pp)pGpp synthetases from other organisms. It is clear that while C. difficile utilizes magic spot signaling, its mechanisms of alarmone synthesis are not directly homologous to those in more completely characterized organisms.

microbiology↗