Next generation tools for high-throughput promoter and expression analysis employing single-copy knock-ins at the Hprt1 locus.

We have engineered a set of useful tools that facilitate targeted single copy knock-in (KI) at the hypoxanthine guanine phosphoribosyl transferase 1 (Hprt1) locus. We employed fine scale mapping to delineate the precise breakpoint location at the Hprt1(b-m3) locus allowing allele specific PCR assays to be established. Our suite of tools contains four targeting expression vectors and a complementing series of embryonic stem cell lines. Two of these vectors encode enhanced green fluorescent protein (EGFP) driven by the human cytomegalovirus immediate-early enhancer/modified chicken beta-actin (CAG) promoter, whereas the other two permit flexible combinations of a chosen promoter combined with a reporter and/or gene of choice. We have validated our tools as part of the Pleiades Promoter Project (http://www.pleiades.org), with the generation of brain-specific EGFP positive germline mouse strains.

Infant serotonin transporter (SLC6A4) promoter genotype is associated with adverse neonatal outcomes after prenatal exposure to serotonin reuptake inhibitor medications.

Reduced Apgar scores and birth weight, increased risk of respiratory distress, jitteriness and increased tone have been reported in up to 30% of neonates with prenatal exposure to serotonin reuptake inhibitor (SRI) antidepressant medications. In adults, effects of these medications may be related to the genotype for the serotonin transporter (SLC6A4) promoter. In this study we investigated whether SLC6A4 genotype influences the risk for adverse outcomes in neonates with prenatal SRI exposure. Neonatal outcomes including Apgar scores, birth weight, gestational age at birth, symptoms of poor neonatal adaptation and genotype for SLC6A4 were determined in 37 prenatally SRI exposed neonates and compared with 47 non-exposed neonates. Reduced 5 min Apgar scores were observed in exposed neonates and this was moderated by the ss genotype (P<0.001). Birth weight was lower in exposed ls neonates (P=0.008). Risk for respiratory symptoms (respiratory distress and rapid breathing) was higher in exposed neonates with the ll genotype compared to non-exposed neonates (P<0.05) and risk for neuromotor symptoms increased in exposed ss neonates (P<0.026). These relationships remained when controlling for maternal mood during pregnancy, length of gestational medication exposure and gestational age at birth and cesarean section rate. Prenatal SRI exposure was associated with adverse neonatal outcomes and these effects were moderated by infant SLC6A4 genotype. Relationships between polymorphisms and specific outcomes varied during the neonatal period, suggesting that beyond apparent gene-medication interactions, multiple mechanisms contribute to adverse neonatal outcomes following prenatal SRI exposure.