jar was identified as a new class of unconventional myosin with a head domain 29-33% identical to other myosins, containing ATP-binding, actin-binding, and calmodulin-binding motifs.

jar is required for normal actin-based transient membrane furrow formation, nuclear positioning, and actin cap organization in the syncytial blastoderm.

jar catalyzes actin-based, ATP-dependent transport of cytoplasmic particles in living embryos. This was the first direct observation of unconventional myosin-catalyzed transport in living cells.

jar mediates microfilament-dependent transport of particles including mitochondria from nurse cells through ring canals into the oocyte.

jar co-immunoprecipitates with D-CLIP-190 (CLIP-170 homolog), a microtubule-binding protein. They colocalize in neurons and at the posterior pole, suggesting a role in actin-microtubule coordination.

jar is required for follicle cell migration, egg chamber morphogenesis, and imaginal disc morphogenesis. Loss causes aberrant follicle cell shapes and lethality.

jar is a component of the individualization complex (IC) and is essential for spermatid individualization. Partial loss-of-function causes male sterility rescued by transgene expression.

jar is required for border cell migration via stabilization of E-cadherin and Armadillo. jar and Armadillo co-immunoprecipitate.

jar colocalizes with and is required for accumulation of cortactin and Arp2/3 at actin structures during spermatogenesis. jar and dynamin act in parallel to regulate actin dynamics.

jar is required for basal targeting of Miranda and correct spindle orientation in neuroblasts. Miranda directly binds jar.

Review/commentary discussing how myosin VI (Jaguar) transports Miranda basally in neuroblasts for asymmetric cell division.

jar is required for dorsal closure and maintenance of cell-cell adhesion in epithelia. Mutants show cell detachment and irregular epithelial sheets.

Study primarily about myosin V (MyoV). Both myosin V and myosin VI contribute to spermatid individualization, but with distinct roles.

jar stabilizes a branched actin network in actin cones during spermatid individualization. FRAP shows jar tethers rather than transports at cone fronts.

Androcam (Acam) is a testis-specific light chain for jar. They colocalize at actin cone leading edges and co-immunoprecipitate. Androcam replaces calmodulin in the testis.

jar (myosin VI) was identified as a binding partner for the essential light chain by mass spectrometry and co-precipitation.

PP4 phosphatase pathway mediates Miranda complex localization during neuroblast asymmetric divisions. PP4 acts in parallel to or downstream from lgl.

jar (myosin VI) opposes microtubule-based retrograde mitochondrial transport in neurons. Depletion increases retrograde transport velocity and duty cycle.

Multiple cargo-binding partners identified for jar including Cornetto. jar and Cornetto are both required for Hedgehog secretion.

Both motor and cargo-binding domains of jar are required for actin cone localization and function. Conserved partner-binding sites in the tail are critical.

BioReason SFT model describes jar as an actin-based, minus-end-directed motor using an ATP-hydrolyzing head and calmodulin-regulated lever arm. The domain architecture analysis correctly identifies the motor, lever arm, and cargo-binding domains and their functional implications.

CLIP-190 forms F-actin-dependent patches in growth cones mediated by binding to jar (myosin VI). CLIP proteins are not essential for axon extension.

At the larval neuromuscular junction, loss-of-function jar alleles reduce NMJ length and synaptic bouton number, alter synaptic vesicle localization, and perturb basal synaptic transmission and short-term plasticity. Myosin VI is proposed to anchor/tether synaptic vesicles at the bouton periphery. This NMJ synaptic function is not currently captured in GOA annotations for jar.

FM-dye loading and FRAP of GFP-labeled synaptic vesicles show that in jar mutant boutons, newly endocytosed vesicles distribute throughout the bouton rather than peripherally and move more freely, supporting a role for myosin VI in tethering synaptic vesicles to their proper sub-cellular location.

Complete loss of myosin VI is not lethal in Drosophila; the previously reported lethality of the jar322 null allele is most likely due to deletion of a neighboring gene. Null animals are recovered at a lower than expected Mendelian frequency, indicating that jar contributes to robust development without being strictly essential for viability. This supports treating the broad pleiotropic developmental phenotypes as non-core consequences of jar loss.

In planar cell polarity, the activity of Kermit relies on motor proteins including the actin-based myosin VI, which is proposed to help deliver the PCP component Vang to dedicated cellular compartments downstream of Galphao signaling. This places jar/myosin VI in the PCP trafficking network.

Falcon (Edison Scientific) synthesized report confirming jar/Q01989 encodes Drosophila myosin VI (jaguar; Mhc95F), an unconventional actin-based motor that moves toward the minus/pointed end of actin filaments and functions in a context-dependent manner as either a transporter or a tether/anchor. The report consolidates primary evidence for actin-cone stabilization during spermatid individualization (minutes-long actin binding by FRAP), basal Miranda targeting and spindle orientation in neuroblasts, synaptic vesicle tethering at the NMJ, and PCP trafficking. Class VI-specific inserts reverse directionality and slow ADP release to favor long actin association.