Small RNA in situ hybridization in Caenorhabditis elegans, combined with RNA-seq, identifies germline-enriched microRNAs.

Over four hundred different microRNAs (miRNAs) have been identified in the genome of the model organism the nematode Caenorhabditis elegans. As the germline is dedicated to the preservation of each species, and almost half of all the cells in an adult nematode are germline, it is likely that regulatory miRNAs are important for germline development and maintenance. In C. elegans the miR35 family has strong maternal effects, contributing to normal embryogenesis and to adult fecundity. To determine whether any particular miRNAs are greatly enriched in the C. elegans germline we used RNA-seq to compare the miRNA populations in several germline-defective strains of adult C. elegans worms, including glp-4(germline proliferation-4), glh-1(germline helicase-1) and dcr-1(dicer-1). Statistical analyses of RNA-seq comparisons identified 13 miRNAs that are germline-enriched, including seven members of the well-studied miR35 family that were reduced as much as 1000-fold in TaqMan qRT PCR miRNA assays. Along with the miR35s, six others: miR-56 (a member of the miR51 family),-70, -244, -260 , -788 and -4813, none of which previously considered as such, were also identified by RNA-seq as germline-enriched candidates. We went on to develop a successful miRNA in situ hybridization protocol for C. elegans, revealing miR35s specifically concentrate during oogenesis in the pachytene region of the gonad, and persist throughout early embryogenesis, while in adult animals neither let-7 nor miR-228 has a germline-bias.

Reevaluation of recent criteria for blood exchange transfusion in term infants with hyperbilirubinemia.

For hyperbilirubinemic infants treated according to the higher criterion for a blood exchange transfusion (BET), auditory brainstem response (ABR) was performed to evaluate whether the treatment was adequate. Twenty hyperbilirubinemic infants were collected as the study group. They were divided into 2 groups; group A consisted of 17 infants receiving intensive phototherapy only, while group B consisted of 3 infants receiving BET plus phototherapy. Fourteen healthy neonates were collected as the control group. Language development was evaluated with "language/communication development milestone: infancy through school-age" at the age of 5 months to 3 years old. Wave V at 30 dB HL was clearly identified in all infants in group A and in the control group. There was no significant difference in the latency between them (p > 0.05). In group A, peak bilirubin levels of 16 cases reached the former criteria for BET Their ABRs were normal. Language development was normal in 12 cases, while 4 cases were lost to follow-up. In group B, 2 cases had abnormal ABRs, while the third had normal ABR and language development. By analyzing the condition of these babies, we could conclude that in addition to peak bilirubin level and age, other factors such as anemia, the duration of hyperbilirubinemia, and the decline rate of bilirubin in response to intensive phototherapy should also be taken into consideration. For infants with borderline bilirubin levels for BET, we suggest performing BET if they have severe anemia or if intensive phototherapy fails to produce a proper decline in bilirubin.