@article {49143, title = {Juvenile hormone reveals mosaic developmental programs in the metamorphosing optic lobe of Drosophila melanogaster.}, journal = {Biology Open}, year = {2018}, month = {2018 Apr 04}, abstract = {

The development of the adult optic lobe (OL) of is directed by a wave of ingrowth of the photoreceptors over a two day period at the outset of metamorphosis which is accompanied by the appearance of the pupal-specific transcription factor Broad-Z3 (Br-Z3) and expression of early drivers in OL neurons. During this time, there are pulses of ecdysteroids that time the metamorphic events. At the outset, the transient appearance of juvenile hormone (JH) prevents precocious development of the OL caused by the ecdysteroid peak that initiates pupariation, but the artificial maintenance of JH after this time misdirects subsequent development. Axon ingrowth, Br-Z3 appearance and the expression of early drivers were unaffected, but aspects of later development such as the dendritic expansion of the lamina monopolar neurons and the expression of late drivers were suppressed. This effect of the exogenous JH mimic (JHM) pyriproxifen is lost by 24 hr after pupariation. Part of this effect of JHM is due to its suppression of the appearance of ecdysone receptor EcR-B1 that occurs after pupation and during early adult development.

}, issn = {2046-6390}, doi = {10.1242/bio.034025}, author = {Riddiford, Lynn M and Truman, James W and Nern, Aljoscha} } @article {5635, title = {The juvenile hormone signaling pathway in insect development.}, journal = {Annual Review of Entomology}, volume = {58}, year = {2013}, month = {2013 Jan 7}, pages = {181-204}, abstract = {

The molecular action of juvenile hormone (JH), a regulator of vital importance to insects, was until recently regarded as a mystery. The past few years have seen an explosion of studies of JH signaling, sparked by a finding that a JH-resistance gene, Methoprene-tolerant (Met), plays a critical role in insect metamorphosis. Here, we summarize the recently acquired knowledge on the capacity of Met to bind JH, which has been mapped to a particular ligand-binding domain, thus establishing this bHLH-PAS protein as a novel type of an intracellular hormone receptor. Next, we consider the significance of JH-dependent interactions of Met with other transcription factors and signaling pathways. We examine the regulation and biological roles of genes acting downstream of JH and Met in insect metamorphosis. Finally, we discuss the current gaps in our understanding of JH action and outline directions for future research.

}, issn = {1545-4487}, doi = {10.1146/annurev-ento-120811-153700}, author = {Jindra, Marek and Palli, Subba R and Riddiford, Lynn M} } @article {2499, title = {Juvenile hormone action: a 2007 perspective.}, journal = {Journal of Insect Physiology}, volume = {54}, year = {2008}, month = {2008 Jun}, pages = {895-901}, abstract = {

Juvenile hormone (JH) is a key hormone in regulation of the insect{\textquoteright}s life history, both in maintaining the larval state during molts and in directing reproductive maturation. This short review highlights the recent papers of the past year that lend new insight into the role of this hormone in the larva and the mechanisms whereby it achieves this role.

}, keywords = {Animals, Basic Helix-Loop-Helix Transcription Factors, Biological, DNA-Binding Proteins, Drosophila Proteins, Insects, Juvenile Hormones, Larva, Metamorphosis, Response Elements, Transcription Factors}, issn = {0022-1910}, doi = {10.1016/j.jinsphys.2008.01.014}, author = {Riddiford, Lynn M} }