FlyBase Allele Report: Dmel\cno[R2]

Type II neuroblast lineage MARCM clones mutant for cno^R2 display reduced neuroblast (NB) size, occasional appearance of more than one NB per lineage, fewer mature intermediate neural precursors and ganglion mother cells (relative to wild-type clones), as well as mislocalization or absence of major asymmetric cell division regulators in metaphase/anaphase NBs, the clones however do not show a tumor-like overgrowth in third instar larvae. cno^R2 mutant clones in the antennal disc also do not overgrow.

(Rives-Quinto et al., 2017)

cno^R2 mutants look largely or completely normal through the onset of dorsal closure. Adherens junctions are maintained throughout, with no substantial differences in the accumulation of shg. At the onset of dorsal closure, both leading edge cells and more ventral epidermal cells are able to elongate. In most cno^R2 mutants, the actin cable at the leading edge becomes uneven as leading edge cell chapes become non-uniform, with the cable reduced or lost in cells with splayed, open leading edges.

The leading edge in cno^R2 mutant embryos is wavy rather than straight. Leading edge cells in cno^R2 mutants are very uneven in shape; some cells display hyperconstricted leading edges, whereas in other cells the leading edge is broadened. Zipping together of the two epidermal sheets at the canthi is also significantly slowed, and thus the dorsal opening is oval rather than 'eye-shaped'. Many mutant embryos fails to close before the onset of muscle contractions and amnioserosal apoptosis; this leads to ripping of the amnioserosa, and ultimately some embryos aer left totally open dorsally. In those that do close, cell shapes remain abnormal and small holes sometimes remain. In addition, segmental grooves in cno^R2 mutant embryos remain exceptionally deep even after closure should be finished, both dorsally and ventrally.

Approximately 84% of cno^R2 zygotic mutants display defects in head involution, ranging from mild to severe defects in the head skeleton hole, while 16% display a head or dorsal cuticle hole, indicating failure of head involution and/or dorsal closure.

(Choi et al., 2011)

Zygotic cno^R2 mutant embryos die; 88% have defects in head involution but close dorsally, whereas 11% have defects in head involution and dorsal closure. Loss of maternal cno^R2 is not fully rescued by zygotic wild-type cno; ~30% of paternally rescued mutants die with defects in head involution. cno^R2 maternal+zygotic mutants are much more severe than zygotic mutants, which is consistent with strong maternal contribution. Most maternal/zygotic cno^R2 embryos (83%) entirely lack ventral cuticle, but retain dorsal cuticle.

Initial adherens junctions in cno^R2 maternal and zygotic mutants is indistinguishable from wild-type. Maturation of spot adherens junctions to belt adherens junctions also proceeds normally.

cno^R2 mutants do not completely internalize mesoderm during gastrulation (as in wild-type); many cells remain on the embryo surface and begin to divide in this aberrant location.

While cno^R2 mutant mesodermal cells initiate constriction fairly synchronously, they arrest partway through apical constriction. The phenotype is variable. In less severe mutants, constriction goes at the same rate as in wild-type but halts prematurely. In more severe embryos, constriction is slower than in wild-type, and more cells lag behind. cno^R2 cells apically constrict without fully effective linkage between adherens junctions and the actomyosin network, the contractile network detaches from adherens junctions before full cell constriction, and mesodermal cells are not efficiently internalized. cno^R2 mutants successfully internalize the gut, although the midgut epithelium may be less organised.

Ectodermal cells in cno^R2 mutants planar polarize myosin and adherens junction proteins in an even more pronounced manner than wild-type. They retain accentuated planar polarity through the end of germband extension.

(Sawyer et al., 2009)

External Data

Linkouts

Interactions

Show genetic interaction network for Enhancers & Suppressors

Phenotypic Class

Enhanced by

Statement

Reference

cno^R2 has abnormal cell shape phenotype, enhanceable by ena²³/ena[+]

(Choi et al., 2011)

NOT Enhanced by

Statement

Reference

cno^R2 has abnormal cell number | third instar larval stage | somatic clone phenotype, non-enhanceable | somatic clone by Ras85D^ΔC40B/Ras85D^ΔC40B

(Rives-Quinto et al., 2017)

cno^R2 has abnormal neuroanatomy | third instar larval stage | somatic clone phenotype, non-enhanceable by dlg1^GD4689/Scer\GAL4^Dll-md23

(Rives-Quinto et al., 2017)

cno^R2 has abnormal cell number | third instar larval stage | somatic clone phenotype, non-enhanceable by dlg1^GD4689/Scer\GAL4^Dll-md23

(Rives-Quinto et al., 2017)

cno^R2 has decreased cell size | third instar larval stage | somatic clone phenotype, non-enhanceable by dlg1^GD4689/Scer\GAL4^Dll-md23

(Rives-Quinto et al., 2017)

cno^R2 has abnormal neuroanatomy | third instar larval stage | somatic clone phenotype, non-enhanceable by l(2)gl^KK100777/Scer\GAL4^Dll-md23

(Rives-Quinto et al., 2017)

cno^R2 has abnormal cell number | third instar larval stage | somatic clone phenotype, non-enhanceable by l(2)gl^KK100777/Scer\GAL4^Dll-md23

(Rives-Quinto et al., 2017)

cno^R2 has decreased cell size | third instar larval stage | somatic clone phenotype, non-enhanceable by l(2)gl^KK100777/Scer\GAL4^Dll-md23

(Rives-Quinto et al., 2017)

Suppressed by

Statement

Reference

cno^R2, scrib¹ has neoplasia | somatic clone | third instar larval stage phenotype, suppressible | somatic clone by Ras85D^KK108029/Scer\GAL4^Dll-md23

(Rives-Quinto et al., 2017)

cno^R2, scrib¹ has abnormal neuroanatomy | somatic clone | third instar larval stage phenotype, suppressible | somatic clone by Ras85D^KK108029/Scer\GAL4^Dll-md23

(Rives-Quinto et al., 2017)

cno^R2, scrib¹ has abnormal size | somatic clone | third instar larval stage phenotype, suppressible | somatic clone by Ras85D^KK108029/Scer\GAL4^Dll-md23

(Rives-Quinto et al., 2017)

cno^R2, scrib¹ has increased cell number | somatic clone | third instar larval stage phenotype, suppressible | somatic clone by Ras85D^KK108029/Scer\GAL4^Dll-md23

(Rives-Quinto et al., 2017)

cno^R2 has abnormal neuroanatomy | somatic clone | third instar larval stage phenotype, suppressible | partially | somatic clone by Ras85D^ΔC40B/Ras85D^ΔC40B

(Rives-Quinto et al., 2017)

cno^R2 has decreased cell size | somatic clone | third instar larval stage phenotype, suppressible | somatic clone by Ras85D^ΔC40B/Ras85D^ΔC40B

(Rives-Quinto et al., 2017)

cno^R2, scrib¹ has neoplasia | somatic clone | third instar larval stage phenotype, suppressible | somatic clone by cno^UAS.cBa/Scer\GAL4^Dll-md23

(Rives-Quinto et al., 2017)

cno^R2, scrib¹ has abnormal neuroanatomy | somatic clone | third instar larval stage phenotype, suppressible | somatic clone by cno^UAS.cBa/Scer\GAL4^Dll-md23

(Rives-Quinto et al., 2017)

cno^R2, scrib¹ has abnormal size | somatic clone | third instar larval stage phenotype, suppressible | somatic clone by cno^UAS.cBa/Scer\GAL4^Dll-md23

(Rives-Quinto et al., 2017)

cno^R2, scrib¹ has increased cell number | somatic clone | third instar larval stage phenotype, suppressible | somatic clone by cno^UAS.cBa/Scer\GAL4^Dll-md23

(Rives-Quinto et al., 2017)

cno^R2, scrib¹ has neoplasia | somatic clone | third instar larval stage phenotype, suppressible | somatic clone by Scer\GAL4^Dll-md23/Akt^KK100495

(Rives-Quinto et al., 2017)

cno^R2, scrib¹ has abnormal neuroanatomy | somatic clone | third instar larval stage phenotype, suppressible | somatic clone by Scer\GAL4^Dll-md23/Akt^KK100495

(Rives-Quinto et al., 2017)

cno^R2, scrib¹ has abnormal size | somatic clone | third instar larval stage phenotype, suppressible | somatic clone by Scer\GAL4^Dll-md23/Akt^KK100495

(Rives-Quinto et al., 2017)

cno^R2, scrib¹ has increased cell number | somatic clone | third instar larval stage phenotype, suppressible | somatic clone by Scer\GAL4^Dll-md23/Akt^KK100495

(Rives-Quinto et al., 2017)

cno^R2, scrib¹ has neoplasia | somatic clone | third instar larval stage phenotype, suppressible by Scer\GAL4^Dll-md23/Mmmm\ras^N17.UAS

(Rives-Quinto et al., 2017)

cno^R2, scrib¹ has abnormal neuroanatomy | somatic clone | third instar larval stage phenotype, suppressible | somatic clone by Scer\GAL4^Dll-md23/Mmmm\ras^N17.UAS

(Rives-Quinto et al., 2017)

cno^R2, scrib¹ has abnormal size | somatic clone | third instar larval stage phenotype, suppressible | somatic clone by Scer\GAL4^Dll-md23/Mmmm\ras^N17.UAS

(Rives-Quinto et al., 2017)

cno^R2, scrib¹ has increased cell number | somatic clone | third instar larval stage phenotype, suppressible | somatic clone by Scer\GAL4^Dll-md23/Mmmm\ras^N17.UAS

(Rives-Quinto et al., 2017)

NOT suppressed by

Statement

Reference

cno^R2, scrib¹ has neoplasia | somatic clone | third instar larval stage phenotype, non-suppressible | somatic clone by cno^UAS.cBa/Scer\GAL4^Dll-md23

(Rives-Quinto et al., 2017)

cno^R2, scrib¹ has abnormal neuroanatomy | somatic clone | third instar larval stage phenotype, non-suppressible | somatic clone by cno^UAS.cBa/Scer\GAL4^Dll-md23

(Rives-Quinto et al., 2017)

cno^R2, scrib¹ has abnormal size | somatic clone | third instar larval stage phenotype, non-suppressible | somatic clone by cno^UAS.cBa/Scer\GAL4^Dll-md23

(Rives-Quinto et al., 2017)

cno^R2, scrib¹ has increased cell number | somatic clone | third instar larval stage phenotype, non-suppressible | somatic clone by cno^UAS.cBa/Scer\GAL4^Dll-md23

(Rives-Quinto et al., 2017)

cno^R2, scrib¹ has neoplasia | somatic clone | third instar larval stage phenotype, non-suppressible | somatic clone by Raf^KK100982/Scer\GAL4^Dll-md23

(Rives-Quinto et al., 2017)

cno^R2, scrib¹ has abnormal neuroanatomy | somatic clone | third instar larval stage phenotype, non-suppressible | somatic clone by Raf^KK100982/Scer\GAL4^Dll-md23

(Rives-Quinto et al., 2017)

cno^R2, scrib¹ has abnormal size | somatic clone | third instar larval stage phenotype, non-suppressible | somatic clone by Raf^KK100982/Scer\GAL4^Dll-md23

(Rives-Quinto et al., 2017)

cno^R2, scrib¹ has increased cell number | somatic clone | third instar larval stage phenotype, non-suppressible | somatic clone by Raf^KK100982/Scer\GAL4^Dll-md23

(Rives-Quinto et al., 2017)

Enhancer of

Statement

Reference

cno^R2/cno[+] is an enhancer of abnormal cell shape phenotype of ena²³

(Choi et al., 2011)

Other

Statement

Reference

cno^R2, sdk^MB05054 has partially lethal | parental effect phenotype

(Gurley et al., 2023)

cno^R2, sdk^MB05054 has abnormal cell adhesion | embryonic stage phenotype

(Letizia et al., 2019)

cno^R2, scrib¹ has neoplasia | somatic clone | third instar larval stage phenotype

(Rives-Quinto et al., 2017)

cno^R2, scrib¹ has increased cell number | somatic clone | third instar larval stage phenotype

(Rives-Quinto et al., 2017)

cno^R2, scrib¹ has abnormal neuroanatomy | somatic clone | third instar larval stage phenotype

(Rives-Quinto et al., 2017)

cno^R2, scrib¹ has abnormal size | somatic clone | third instar larval stage phenotype

(Rives-Quinto et al., 2017)

Phenotype Manifest In

Enhanced by

Statement

Reference

cno^R2 has type II neuroblast | third instar larval stage | somatic clone phenotype, enhanceable | somatic clone by scrib¹/scrib¹

(Rives-Quinto et al., 2017)

cno^R2 has embryo | dorsal closure stage phenotype, enhanceable by ena²³/ena[+]

(Choi et al., 2011)

cno^R2 has embryonic leading edge cell phenotype, enhanceable by ena²³/ena[+]

(Choi et al., 2011)

cno^R2 has ventral head epidermis phenotype, enhanceable by ena²³/ena[+]

(Choi et al., 2011)

cno^R2 has embryonic head phenotype, enhanceable by ena²³/ena[+]

(Choi et al., 2011)

NOT Enhanced by

Statement

Reference

cno^R2 has type II neuroblast | third instar larval stage | somatic clone phenotype, non-enhanceable by dlg1^GD4689/Scer\GAL4^Dll-md23

(Rives-Quinto et al., 2017)

cno^R2 has type II neuroblast | third instar larval stage | somatic clone phenotype, non-enhanceable by l(2)gl^KK100777/Scer\GAL4^Dll-md23

(Rives-Quinto et al., 2017)

Suppressed by

Statement

Reference

cno^R2, scrib¹ has larval brain | somatic clone | third instar larval stage phenotype, suppressible | somatic clone by Scer\GAL4^Dll-md23/Mmmm\ras^N17.UAS

(Rives-Quinto et al., 2017)

cno^R2, scrib¹ has larval brain | somatic clone | third instar larval stage phenotype, suppressible | somatic clone by Ras85D^KK108029/Scer\GAL4^Dll-md23

(Rives-Quinto et al., 2017)

cno^R2, scrib¹ has larval brain | somatic clone | third instar larval stage phenotype, suppressible | somatic clone by cno^UAS.cBa/Scer\GAL4^Dll-md23

(Rives-Quinto et al., 2017)

cno^R2, scrib¹ has larval brain | somatic clone | third instar larval stage phenotype, suppressible | somatic clone by Scer\GAL4^Dll-md23/Akt^KK100495

(Rives-Quinto et al., 2017)

NOT suppressed by

Statement

Reference

cno^R2, scrib¹ has larval brain | somatic clone | third instar larval stage phenotype, non-suppressible | somatic clone by cno^UAS.cBa/Scer\GAL4^Dll-md23

(Rives-Quinto et al., 2017)

cno^R2, scrib¹ has larval brain | somatic clone | third instar larval stage phenotype, non-suppressible | somatic clone by Raf^KK100982/Scer\GAL4^Dll-md23

(Rives-Quinto et al., 2017)

Enhancer of

Statement

Reference

cno^R2/cno^R2 is an enhancer of type II neuroblast | third instar larval stage | somatic clone phenotype of scrib¹

(Rives-Quinto et al., 2017)

cno^R2/cno^R2 is an enhancer of antennal disc | third instar larval stage | somatic clone phenotype of scrib¹

(Rives-Quinto et al., 2017)

cno^R2/cno^R2 is an enhancer | somatic clone of antennal disc | third instar larval stage | somatic clone phenotype of Scer\GAL4^Dll-md23, dlg1^GD4689

(Rives-Quinto et al., 2017)

cno^R2/cno^R2 is an enhancer | somatic clone of antennal disc | third instar larval stage | somatic clone phenotype of Scer\GAL4^Dll-md23, l(2)gl^KK100777

(Rives-Quinto et al., 2017)

cno^R2/cno[+] is an enhancer of embryo | dorsal closure stage phenotype of ena²³

(Choi et al., 2011)

cno^R2/cno[+] is an enhancer of embryonic leading edge cell phenotype of ena²³

(Choi et al., 2011)

cno^R2/cno[+] is an enhancer of ventral head epidermis phenotype of ena²³

(Choi et al., 2011)

cno^R2/cno[+] is an enhancer of embryonic head phenotype of ena²³

(Choi et al., 2011)

Other

Statement

Reference

cno^R2, sdk^MB05054 has embryo | parental effect phenotype

(Gurley et al., 2023)

cno^R2, sdk^MB05054 has embryonic head | parental effect phenotype

(Gurley et al., 2023)

cno^R2, sdk^MB05054 has embryonic/larval tracheal section | embryonic stage phenotype

(Letizia et al., 2019)

cno^R2, scrib¹ has larval brain | somatic clone | third instar larval stage phenotype

(Rives-Quinto et al., 2017)

cno^R2, scrib¹ has type II neuroblast | increased number | somatic clone | third instar larval stage phenotype

(Rives-Quinto et al., 2017)

cno^R2, scrib¹ has intermediate neuronal progenitor | increased number | somatic clone | third instar larval stage phenotype

(Rives-Quinto et al., 2017)

Additional Comments

Genetic Interactions

Statement

Reference

Stage 15-16 sdk^MB05054 cno^R2 and sdk^MB05054 Df(3R)pyd^B12 double heterozygous embryos exhibit incomplete tracheal cell intercalation (many tracheal branches still maintain intercellular junctions) similar to sdk^MB05054 homozygotes and different than controls.

(Letizia et al., 2019)

Type II neuroblast lineage MARCM clones double mutant for cno^R2 and scrib¹ display a strong tumor-like overgrowth with clone areas significantly larger than either of the single mutant clones or the control wild-type clones in third instar larvae. The cno^R2;scrib¹ clones are composed of almost exclusively of progenitor cells (dpn-positive) with few differentiated cells and in respect to overgrowth capacity fall into two categories - about half of the clones does not overgrow while the other half does, about a third of which massively so. The double mutant clones contain significantly more neuroblast and intermediate neural progenitor (INP) cells compared to wild-type clones but the relative proportion of mature INPs is reduced (although their absolute number per clone is also increased). The asymmetric localization major asymmetric cell division regulators in metaphase/anaphase NBs fails in all the mutant clones. The overgrowth and increased number of progenitor cells characteristic for cno^R2;scrib¹ clones is significantly suppressed by Scer\GAL4^Dll-md23-driven expression of Ras85D^KK108029, cno^Scer\UAS.cBa or Akt1^KK100495, but not cno^ΔN.Scer\UAS or Raf^KK100982 in the mutant clones. The reduced number of progenitor cells in cno^R2 clones is not significantly affected by combination with Ras85D^ΔC40B, but the morphology and size of the clones and the neuroblasts within them is more similar to wild-type. The decreased size of neuroblasts in the cno^R2 clones is not affected by expression of either dlg1^GD4689 or l(2)gl^KK100777 (driven by Scer\GAL4^Dll-md23) in the clones.

The tumor-like overgrowth of MARCM clones in larval antennal disc expressing either dlg1^GD4689 or l(2)gl^KK100777 under the control of Scer\GAL4^Dll-md23 is not significantly worsened by cno^R2 homozygosity but the cellular and tissue morphology and disorganization are exacerbated.

(Rives-Quinto et al., 2017)

An ena²³ heterozygous background enhances the cno^R2 zygotic phenotype, with 38% of progeny exhibiting head and/or dorsal holes, and 4% displaying a novel, stronger phenotype in which only the ventral cuticle remains.

Reducing maternal and zygotic cno^R2 levels strongly enhances the ena²³ zygotic phenotype, with 50% of the progeny exhibiting head holes.

cno^R2 ena²³ double mutants fail to complete dorsal closure.

(Choi et al., 2011)

Xenogenetic Interactions

Statement

Reference

The overgrowth and increased number of progenitor cells characteristic for cno^R2;scrib¹ double mutant MARCM clones is significantly suppressed by Scer\GAL4^Dll-md23-driven expression of Mmmm\ras^N17.Scer\UAS in the mutant clones.

(Rives-Quinto et al., 2017)

Complementation and Rescue Data

Comments

Images (0)

Mutant

Wild-type

Stocks (1)

Bloomington

94716

P{neoFRT}82B cno^R2/TM3, Sb¹

Notes on Origin

Discoverer

Separable from: mesh^R2.

(Chen and St Johnston, 2022)

External Crossreferences and Linkouts ( 0 )

Synonyms and Secondary IDs (2)

Reported As

Symbol Synonym

canoe^R2

(Chen and St Johnston, 2022)

cno^R2

(Jensen et al., 2025, McParland et al., 2024, McParland et al., 2024, Gurley et al., 2023, Peifer et al., 2023, Perez-Vale et al., 2021, Yu and Zallen, 2020, Letizia et al., 2019, Schmidt et al., 2018, Rives-Quinto et al., 2017, Pérez-Gómez et al., 2013, Choi et al., 2011, Sawyer et al., 2009)

Name Synonyms

Secondary FlyBase IDs

References (14)

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