Hcfc1a regulates neural precursor proliferation and asxl1 expression in the developing brain

Abstract

Background Precise regulation of neural precursor cell (NPC) proliferation and differentiation is essential to ensure proper brain development and function. The HCFC1 gene encodes a transcriptional co-factor that regulates cell proliferation, and previous studies suggest that HCFC1 regulates NPC number and differentiation. However, the molecular mechanism underlying these cellular deficits has not been completely characterized. Methods Here we created a zebrafish harboring mutations in the hcfc1a gene (the hcfc1aco60/+ allele), one ortholog of HCFC1, and utilized immunohistochemistry and RNA-sequencing technology to understand the function of hcfc1a during neural development. Results The hcfc1aco60/+ allele results in an increased number of NPCs and increased expression of neuronal and glial markers. These neural developmental deficits are associated with larval hypomotility and the abnormal expression of asxl1, a polycomb transcription factor, which we identified as a downstream effector of hcfc1a. Inhibition of asxl1 activity and/or expression in larvae harboring the hcfc1aco60/+ allele completely restored the number of NPCs to normal levels. Conclusion Collectively, our data demonstrate that hcfc1a regulates NPC number, NPC proliferation, motor behavior, and brain development.

Knockdown of hspg2 is associated with abnormal mandibular joint formation and neural crest cell dysfunction in zebrafish

“…In addition, we designed a splice inhibiting morpholino to the 3′ splice acceptor of exon 2, but the designed morpholino did not delete exon 3 as predicted, even at the highest concentration injected (2 nl of a 0.9 mM stock solution). We did, however, utilize a random control morpholino to account for the possibility of morpholino-induced cell death, an endeavor that proved to be rather successful in previous studies [ 54 , 55 ]. And, while injection of HS side chains is a potential rescue for the morphant phenotype we observe, there is the possibility that HS/heparin co-injection would fail to rescue because a domain outside of domain I is also essential for regulation of CNCCs.…”

“…AVMA guidelines for embryos younger than 7 DPF were followed, which indicate 1–10% sodium hypochlorite solution following anesthesia. Detailed methods for anesthesia and euthanasia have been previously described [ 54 ].…”

“…For all experiments, the morphant experimental group is compared to either a random control group or wildtype non-injected. The randomized control morpholino has been shown through previous literature to have no associated phenotypes, indicating that it does not influence final results and therefore is the appropriate control group for comparison [ 54 , 55 , 57 ]. Thus, for statistical analysis, comparisons were performed using a T-test between the random control group and the morpholino.…”

Knockdown of hspg2 is associated with abnormal mandibular joint formation and neural crest cell dysfunction in zebrafish

“…In addition, we designed a splice inhibiting morpholino to the 3' splice acceptor of exon 2, but the designed morpholino did not delete exon 3 as predicted, even at the highest concentration injected (2nl of a 0.9mM stock solution). We did, however, utilize a random control morpholino to account for the possibility of morpholino-induced cell death, an endeavor that proved to be rather successful in previous studies (54,55). And, while injection of HS side chains is a potential rescue for the morphant phenotype we observe, there is the possibility that HS/heparin coinjection would fail to rescue because a domain outside of domain I is also essential for regulation of CNCCs.…”

“…For all experiments, the morphant experimental group is compared to either a random control group or wildtype non-injected. The randomized control morpholino has been shown through previous literature to have no associated phenotypes, indicating that it does not in uence nal results and therefore is the appropriate control group for comparison (54,55,57). Thus, for statistical analysis, comparisons were performed using a T-test between the random control group and the morpholino.…”