laminin, lamA, laminin α, hdln, Lam-A
laminin - extracellular matrix protein - plays a role in the pathfinding process of ocellar axons - activity-dependent retrograde laminin A signaling regulates synapse growth at Drosophila neuromuscular junctions
Low-frequency RNA-Seq exon junction(s) not annotated.
Gene model reviewed during 5.45
There is only one protein coding transcript and one polypeptide associated with this gene
Laminin is a complex glycoprotein, consisting of three different polypeptide chains (alpha, beta, gamma), which are bound to each other by disulfide bonds into a cross-shaped molecule comprising one long and three short arms with globules at each end.
The alpha-helical domains I and II are thought to interact with other laminin chains to form a coiled coil structure.
Domains VI, IV and G are globular.
Click to get a list of regulatory features (enhancers, TFBS, etc.) and gene disruptions (point mutations, indels, etc.) within or overlapping Dmel\LanA using the Feature Mapper tool.
Comment: reported as head epidermis primordium
Comment: reported as head epidermis primordium
LanA transcripts are detected in 4-6hr embryos, peak at 10-12hr, and then decline. Later peaks occur in early larvae, and late pupae. Developmental increases in Laminin transcripts are associated with periods of morphogenesis and precede those of Col4a1 transcripts. Laminin transcripts appear in newly formed mesoderm and are later expressed in fat body, in some glial cells and prominantly in hemocytes found distributed around many organs where basement membrane deposition occurs such as brain, nerve cord, sensory organs, and various internal organs. LanA transcripts are detected at a lower level than LanB1 and LanB2 transcripts.
LanA expression is first detected during germ band extension in the mesoderm and at lower levels in the ectoderm including the neurogenic region. At ~8hr, the level of LanA expression dramatically increases in both the somatic and visceral mesoderm and expression in these tissues continues through the rest of embryonic development. At 8hr, expression in the ectoderm also increases but mainly in the epidermis and not in ectodermal derivatives such as the salivary glands and the CNS. The only LanA expression in the CNS is found along the midline. The interface glia were also tentatively identified as a site of LanA expression. The patterns of expression of LanA, LanB1, and LanB2 are nearly identical.
LanA protein is detected in embryonic hemocytes and fat body. In later embryos, LanA protein is observed in basement membranes surrounding the nerve cord, brain, gut, spiracles, sensory bodies, and muscles.
In dissected embryos between 10-13 hours of development, LanA is detected in basement membrane throughout the embryo. These include basement membranes covering the inside of the epidermis, developing muscles, gut, and internal glands and organs. LanA is also detected in the dorsal basement membrane overlying the developing CNS and in a prominent pair of mesodermal cells just dorsal to the nervous system. The most striking staining in the developing CNS is seen along the axon pathways, including the longitudinal pathways, the commissural pathways, and the peripheral nerve roots. The glia around the peripheral nerve roots also stain. Staining is also observed surrounding clusters of peripheral sensory organs and their support cells. All three Laminin subunits show similar patterns of staining.
GBrowse - Visual display of RNA-Seq signalsView Dmel\LanA in GBrowse 2
Please Note This section lists cDNAs and ESTs that fall within the genomic extent of the gene model, which may include cDNAs and ESTs of genes within introns, or of overlapping genes. Please see GBrowse for alignment of the cDNAs and ESTs to the gene model.
For each fully sequenced cDNA the DGRC maintains various forms of the cDNA (e.g tagged or untagged) in several different host vectors for subsequent cloning and expression in Drosophila and Drosophila cell lines.
Source for identity of: LanA CG10236
dsRNA made from templates generated with primers directed against this gene tested in RNAi screen for effects on Kc167 and S2R+ cell morphology.
LanA is not required for heart morphogenesis, but does play a role in the maintenance of the heart's ultrastructure.
In a sample of 79 genes with multiple introns, 33 showed significant heterogeneity in G+C content among introns of the same gene and significant positive correspondence between the intron and the third codon position G+C content within genes. These results are consistent with selection adding against preferred codons at the start of genes.
Chain-specific polyclonal antibodies reveal that LanB1 and LanB2 form a stable dimer before they are disulfide-bonded to each other. LanA associates with neither monomeric LanB1, monomeric LanB2 nor LanB1 LanB2 dimer without disulfide-bonding but only with disulfide-bonded LanB1 LanB2 dimer to form LanA LanB1 LanB2 trimers. Results demonstrate that the interchain disulfide-bonding between LanB1 and LanB2 is essential for LanA LanB1 LanB2 trimer formation.
Extracellular matrix containing LanA gene product is required for ocellar axon pathfinding.
Cell attachment activities of LanA peptides suggest that active regions in the G domain play an important role in cell surface receptor interactions.
Examination of mutant embryos and the function of Msp-300 during embryonic muscle development suggests a functional link between LanA and Msp-300 in the development of the embryonic somatic musculature.
Mutations of LanA show striking abnormalities in growth cone guidance of ocellar pioneer (OP) axons.
LanA function is not required for the early phases of mesoderm patterning and morphogenesis in embryos at the extended germ band stage. Function is required for the proper morphogenesis of the heart, somatic mesoderm and gut during later stages of embryonic development. The endoderm fails to undergo the initial columnar polarisation in the absence of functional LanA. These results indicate that the primary function of LanA is to provide structural support for the various cell types, enabling their proper organisation into the various organs.
Clonal analysis revealed that the gene product functions in a non-cell autonomous fashion.
The LanA gene product is required for diverse functions during morphogenesis.
LanA gene cloned and expression pattern studied: changes in expression precede those of Cg25C.
The three Laminin genes (LanA, LanB1 and LanB2) encode the three subunits of Drosophila laminin, which associate to form a cruciform molecule in which the carboxy-terminal ends are α helical and associate with one another and whose amino-terminal ends are free to form three short arms of the cross.