Delayed outpatient follow-up beyond the first 6 weeks after AMI is associated with worse short-term and long-term patient medication adherence. These data support the concept that medication adherence is modifiable via improved care transitions.

Summary How the highly stereotyped morphologies of individual neurons are genetically specified is not well understood. We identify six transcription factors (TFs) expressed in a combinatorial manner in seven post-mitotic adult leg motor neurons (MNs) that are derived from a single neuroblast in Drosophila. Unlike TFs expressed in mitotically active neuroblasts, these TFs do not regulate each other's expression. Removing the activity of a single TF resulted in specific morphological defects, including muscle targeting and dendritic arborization, and in a highly specific walking defect in adult flies. In contrast, when the expression of multiple TFs was modified nearly complete transformations in MN morphologies were generated. These results show that the morphological characteristics of a single neuron are dictated by a combinatorial code of morphology TFs (mTFs). mTFs function at a previously unidentified regulatory tier downstream of factors acting in the NB, but independently of factors that act in terminally differentiated neurons.

SUMMARYAdult Drosophila walk using six multi-jointed legs, each controlled by ~50 leg motoneurons (MNs). Although MNs have stereotyped morphologies, little is known about how they are specified. Here, we describe the function of Hox genes and homothorax (hth), which encodes a Hox co-factor, in Drosophila leg MN development. Removing either Hox or Hth function from a single neuroblast (NB) lineage results in MN apoptosis. A single Hox gene, Antennapedia (Antp), is primarily responsible for MN survival in all three thoracic segments. When cell death is blocked, partially penetrant axon branching errors are observed in Hox mutant MNs. When single MNs are mutant, errors in both dendritic and axon arborizations are observed. Our data also suggest that Antp levels in postmitotic MNs are important for specifying their identities. Thus, in addition to being essential for survival, Hox and hth are required to specify accurate MN morphologies in a level-dependent manner.

Specification of muscle identity in Drosophila is a multistep process: early positional information defines competence groups termed promuscular clusters, from which muscle progenitors are selected, followed by asymmetric division of progenitors into muscle founder cells (FCs). Each FC seeds the formation of an individual muscle with morphological and functional properties that have been proposed to reflect the combination of transcription factors expressed by its founder. However, it is still unclear how early patterning and muscle-specific differentiation are linked. We addressed this question, using Collier (Col; also known as Knot) expression as both a determinant and read-out of DA3 muscle identity. Characterization of the col upstream region driving DA3 muscle specific expression revealed the existence of three separate phases of cis-regulation, correlating with conserved binding sites for different mesodermal transcription factors. Examination of col transcription in col and nautilus (nau) loss-of-function and gainof-function conditions showed that both factors are required for col activation in the 'naïve' myoblasts that fuse with the DA3 FC, thereby ensuring that all DA3 myofibre nuclei express the same identity programme. Together, these results indicate that separate sets of cis-regulatory elements control the expression of identity factors in muscle progenitors and myofibre nuclei and directly support the concept of combinatorial control of muscle identity.