<div><p>(A) Larvae of different genotypes were collected after L2/L3 molt, and the nu... more <div><p>(A) Larvae of different genotypes were collected after L2/L3 molt, and the number of puparia was counted at different time points (<i>x</i>-axis: hours after egg laying). The <i>y</i>-axis shows the percentage of puparia out of all collected third-instar larvae (three vials each with 30 animals; the standard error is shown).</p> <p>(B and C) Ring gland morphology in arrested <i>adgf-a</i> larvae. Approximately 8-d old mutant larva (i.e., 3 d after normal pupariation) with very extensive fat body disintegration (note the transparency of larva in the middle part with small white pieces of fat body) (B). The ring gland dissected from this larva (C) shows morphology of the normal ring gland before the degenerative changes of prothoracic gland starts (compare to schematic diagram to the left of [C], from [<a href="http://www.plosbiology.org/article/info:doi/10.1371/journal.pbio.0030201#plbi-03-07-02-b28" target="_blank">28</a>]).</p> <p>(D–F) Expression of GFP-marked glue protein (SgsΔ3-GFP) in salivary gland of the <i>adgf-a</i> mutant larvae and pupae. All late third-instar larvae express the glue protein as shown on dissected salivary gland (D). Some mutants show typical expulsion from the glands with GFP totally external to the puparial case (E), while others do not expel glue proteins even after puparium formation (F).</p></div
<p>Crystal cells were visualized by heating larvae of different genotypes at 60 °C for 10 m... more <p>Crystal cells were visualized by heating larvae of different genotypes at 60 °C for 10 min [<a href="http://www.plosbiology.org/article/info:doi/10.1371/journal.pbio.0030201#plbi-03-07-02-b46" target="_blank">46</a>]. (A) Wild-type larva, (B) <i>adgf-a</i> single mutant, (C) <i>adoR adgf-a</i> double mutant (scale bar, 0.5 mm).</p
<p>The <i>ADGF-A</i> gene contains four exons and two transcriptional starts [&... more <p>The <i>ADGF-A</i> gene contains four exons and two transcriptional starts [<a href="http://www.plosbiology.org/article/info:doi/10.1371/journal.pbio.0030201#plbi-03-07-02-b17" target="_blank">17</a>,<a href="http://www.plosbiology.org/article/info:doi/10.1371/journal.pbio.0030201#plbi-03-07-02-b47" target="_blank">47</a>]. We analyzed sequences preceding both transcriptional starts for the presence of known transcriptional factor binding sites using the software program Gene2Promoter (Genomatix Software GmbH). Selected sites are represented by color bars in approximate positions of promoter regions. The legend under the sequence show the names of transcription factors binding to matching colored binding sites.</p
Most, but not all cnidarian species in the classes Hydrozoa, Scyphozoa and Anthozoa have a life c... more Most, but not all cnidarian species in the classes Hydrozoa, Scyphozoa and Anthozoa have a life cycle in which a colonial, asexually reproducing hydroid phase alternates with a free-swimming, sexually reproducing medusa phase that, in the hydrozoans, is usually microscopic. Hydrozoan medusae were collected by zooplankton tows in Newport Bay and the Pacific Ocean near Newport Beach, California, and hydroid colonies were collected from solid substrates in the same areas. Specimens were documented by videomicroscopy, preserved in ethanol, and sent to the Canadian Centre for DNA Barcoding at the University of Guelph, Ontario, Canada for DNA barcoding.Among the order Anthomedusae (athecate hydroids), DNA barcoding allowed for the discrimination between the medusae of eight putative species of Bougainvillia, and the hydroid stages were documented for two of these. The medusae of three putative species of Amphinema were identified, and the hydroid stages were identified for two of them. DN...
Many Drosophila genes exist as members of multigene families and within each family the members c... more Many Drosophila genes exist as members of multigene families and within each family the members can be functionally redundant, making it difficult to identify them by classical mutagenesis techniques based on phenotypic screening. We have addressed this problem in a genetic analysis of a novel family of six adenosine deaminase-related growth factors (ADGFs). We used ends-in targeting to introduce mutations into five of the six ADGF genes, taking advantage of the fact that five of the family members are encoded by a three-gene cluster and a two-gene cluster. We used two targeting constructs to introduce loss-of-function mutations into all five genes, as well as to isolate different combinations of multiple mutations, independent of phenotypic consequences. The results show that (1) it is possible to use ends-in targeting to disrupt gene clusters; (2) gene conversion, which is usually considered a complication in gene targeting, can be used to help recover different mutant combination...
Many Drosophila genes exist as members of multigene families and within each family the members c... more Many Drosophila genes exist as members of multigene families and within each family the members can be functionally redundant, making it difficult to identify them by classical mutagenesis techniques based on phenotypic screening. We have addressed this problem in a genetic analysis of a novel family of six adenosine deaminase-related growth factors (ADGFs). We used ends-in targeting to introduce mutations into five of the six ADGF genes, taking advantage of the fact that five of the family members are encoded by a three-gene cluster and a two-gene cluster. We used two targeting constructs to introduce loss-of-function mutations into all five genes, as well as to isolate different combinations of multiple mutations, independent of phenotypic consequences. The results show that (1) it is possible to use endsin targeting to disrupt gene clusters; (2) gene conversion, which is usually considered a complication in gene targeting, can be used to help recover different mutant combinations...
An assessment of humpback whales off west Greenland during July and August 1981 was made by fluke... more An assessment of humpback whales off west Greenland during July and August 1981 was made by fluke photoidentification and strip census methods, in order to determine whether these animals constitute a separate stock or an extended summer range of a stock already identified in the northwest Atlantic. Of 25 individuals sighted, 13 flukes were photographed. None matched whales previously identified in northern feeding areas, but one matched a whale photographed on Silver Bank just north of Hispaniola in the Caribbean in February 1981. Thirty-seven humpbacks were photographed later along the Labrador–Newfoundland coasts. Six of these whales (16%) matched individuals previously identified in the northwest Atlantic. West Greenland humpbacks were not evenly spaced, but were concentrated over the edges of offshore banks. Distribution was unrelated to zooplankton densities, but was positively correlated with large flocks of greater shearwaters. These findings, together with two observations of lunge feeding, confirmed that the humpbacks were eating small fish, probably Ammodytes sp. Our results suggest the possibility of a discrete feeding stock of humpbacks, probably numbering less than 200 whales, off west Greenland which, like other feeding stocks in the northwest Atlantic, breed and calve on Silver and Navidad banks in winter.
Recessive lethal mutations in the fat locus of Drosophila cause hyperplastic, tumor-like overgrow... more Recessive lethal mutations in the fat locus of Drosophila cause hyperplastic, tumor-like overgrowth of larval imaginal discs, defects in differentiation and morphogenesis, and death during the pupal stage. Clones of mutant cells induced by mitotic recombination demonstrate that the overgrowth phenotype is cell autonomous. Here we show that the fat locus encodes a novel member of the cadherin gene superfamily: an enormous transmembrane protein of over 5000 amino acids with a putative signal sequence, 34 tandem cadherin domains, four EGF-like repeats, a transmembrane domain, and a novel cytoplasmic domain. Two recessive lethal alleles contain alterations in the fat coding sequence, and the dominant fat allele, Gull, contains an insertion of a transposable element in the 33rd cadherin domain. Thus, this novel member of the cadherin gene superfamily functions as a tumor suppressor gene and is required for correct morphogenesis.
The effects of various lethal mutations were studied when they were present in the hemizygous sta... more The effects of various lethal mutations were studied when they were present in the hemizygous state as sectors in genetic mosaics (gynandro- morphs) of Drosophila melanogaster. Sixty percent of the lethals studied can survive t3 adulthood in combination with normal tissue in mosaics, whereas the remainder cause the death of such mosaic animals. Some of the gynandro- morph-viable lethals appeared
<div><p>(A) Larvae of different genotypes were collected after L2/L3 molt, and the nu... more <div><p>(A) Larvae of different genotypes were collected after L2/L3 molt, and the number of puparia was counted at different time points (<i>x</i>-axis: hours after egg laying). The <i>y</i>-axis shows the percentage of puparia out of all collected third-instar larvae (three vials each with 30 animals; the standard error is shown).</p> <p>(B and C) Ring gland morphology in arrested <i>adgf-a</i> larvae. Approximately 8-d old mutant larva (i.e., 3 d after normal pupariation) with very extensive fat body disintegration (note the transparency of larva in the middle part with small white pieces of fat body) (B). The ring gland dissected from this larva (C) shows morphology of the normal ring gland before the degenerative changes of prothoracic gland starts (compare to schematic diagram to the left of [C], from [<a href="http://www.plosbiology.org/article/info:doi/10.1371/journal.pbio.0030201#plbi-03-07-02-b28" target="_blank">28</a>]).</p> <p>(D–F) Expression of GFP-marked glue protein (SgsΔ3-GFP) in salivary gland of the <i>adgf-a</i> mutant larvae and pupae. All late third-instar larvae express the glue protein as shown on dissected salivary gland (D). Some mutants show typical expulsion from the glands with GFP totally external to the puparial case (E), while others do not expel glue proteins even after puparium formation (F).</p></div
<p>Crystal cells were visualized by heating larvae of different genotypes at 60 °C for 10 m... more <p>Crystal cells were visualized by heating larvae of different genotypes at 60 °C for 10 min [<a href="http://www.plosbiology.org/article/info:doi/10.1371/journal.pbio.0030201#plbi-03-07-02-b46" target="_blank">46</a>]. (A) Wild-type larva, (B) <i>adgf-a</i> single mutant, (C) <i>adoR adgf-a</i> double mutant (scale bar, 0.5 mm).</p
<p>The <i>ADGF-A</i> gene contains four exons and two transcriptional starts [&... more <p>The <i>ADGF-A</i> gene contains four exons and two transcriptional starts [<a href="http://www.plosbiology.org/article/info:doi/10.1371/journal.pbio.0030201#plbi-03-07-02-b17" target="_blank">17</a>,<a href="http://www.plosbiology.org/article/info:doi/10.1371/journal.pbio.0030201#plbi-03-07-02-b47" target="_blank">47</a>]. We analyzed sequences preceding both transcriptional starts for the presence of known transcriptional factor binding sites using the software program Gene2Promoter (Genomatix Software GmbH). Selected sites are represented by color bars in approximate positions of promoter regions. The legend under the sequence show the names of transcription factors binding to matching colored binding sites.</p
Most, but not all cnidarian species in the classes Hydrozoa, Scyphozoa and Anthozoa have a life c... more Most, but not all cnidarian species in the classes Hydrozoa, Scyphozoa and Anthozoa have a life cycle in which a colonial, asexually reproducing hydroid phase alternates with a free-swimming, sexually reproducing medusa phase that, in the hydrozoans, is usually microscopic. Hydrozoan medusae were collected by zooplankton tows in Newport Bay and the Pacific Ocean near Newport Beach, California, and hydroid colonies were collected from solid substrates in the same areas. Specimens were documented by videomicroscopy, preserved in ethanol, and sent to the Canadian Centre for DNA Barcoding at the University of Guelph, Ontario, Canada for DNA barcoding.Among the order Anthomedusae (athecate hydroids), DNA barcoding allowed for the discrimination between the medusae of eight putative species of Bougainvillia, and the hydroid stages were documented for two of these. The medusae of three putative species of Amphinema were identified, and the hydroid stages were identified for two of them. DN...
Many Drosophila genes exist as members of multigene families and within each family the members c... more Many Drosophila genes exist as members of multigene families and within each family the members can be functionally redundant, making it difficult to identify them by classical mutagenesis techniques based on phenotypic screening. We have addressed this problem in a genetic analysis of a novel family of six adenosine deaminase-related growth factors (ADGFs). We used ends-in targeting to introduce mutations into five of the six ADGF genes, taking advantage of the fact that five of the family members are encoded by a three-gene cluster and a two-gene cluster. We used two targeting constructs to introduce loss-of-function mutations into all five genes, as well as to isolate different combinations of multiple mutations, independent of phenotypic consequences. The results show that (1) it is possible to use ends-in targeting to disrupt gene clusters; (2) gene conversion, which is usually considered a complication in gene targeting, can be used to help recover different mutant combination...
Many Drosophila genes exist as members of multigene families and within each family the members c... more Many Drosophila genes exist as members of multigene families and within each family the members can be functionally redundant, making it difficult to identify them by classical mutagenesis techniques based on phenotypic screening. We have addressed this problem in a genetic analysis of a novel family of six adenosine deaminase-related growth factors (ADGFs). We used ends-in targeting to introduce mutations into five of the six ADGF genes, taking advantage of the fact that five of the family members are encoded by a three-gene cluster and a two-gene cluster. We used two targeting constructs to introduce loss-of-function mutations into all five genes, as well as to isolate different combinations of multiple mutations, independent of phenotypic consequences. The results show that (1) it is possible to use endsin targeting to disrupt gene clusters; (2) gene conversion, which is usually considered a complication in gene targeting, can be used to help recover different mutant combinations...
An assessment of humpback whales off west Greenland during July and August 1981 was made by fluke... more An assessment of humpback whales off west Greenland during July and August 1981 was made by fluke photoidentification and strip census methods, in order to determine whether these animals constitute a separate stock or an extended summer range of a stock already identified in the northwest Atlantic. Of 25 individuals sighted, 13 flukes were photographed. None matched whales previously identified in northern feeding areas, but one matched a whale photographed on Silver Bank just north of Hispaniola in the Caribbean in February 1981. Thirty-seven humpbacks were photographed later along the Labrador–Newfoundland coasts. Six of these whales (16%) matched individuals previously identified in the northwest Atlantic. West Greenland humpbacks were not evenly spaced, but were concentrated over the edges of offshore banks. Distribution was unrelated to zooplankton densities, but was positively correlated with large flocks of greater shearwaters. These findings, together with two observations of lunge feeding, confirmed that the humpbacks were eating small fish, probably Ammodytes sp. Our results suggest the possibility of a discrete feeding stock of humpbacks, probably numbering less than 200 whales, off west Greenland which, like other feeding stocks in the northwest Atlantic, breed and calve on Silver and Navidad banks in winter.
Recessive lethal mutations in the fat locus of Drosophila cause hyperplastic, tumor-like overgrow... more Recessive lethal mutations in the fat locus of Drosophila cause hyperplastic, tumor-like overgrowth of larval imaginal discs, defects in differentiation and morphogenesis, and death during the pupal stage. Clones of mutant cells induced by mitotic recombination demonstrate that the overgrowth phenotype is cell autonomous. Here we show that the fat locus encodes a novel member of the cadherin gene superfamily: an enormous transmembrane protein of over 5000 amino acids with a putative signal sequence, 34 tandem cadherin domains, four EGF-like repeats, a transmembrane domain, and a novel cytoplasmic domain. Two recessive lethal alleles contain alterations in the fat coding sequence, and the dominant fat allele, Gull, contains an insertion of a transposable element in the 33rd cadherin domain. Thus, this novel member of the cadherin gene superfamily functions as a tumor suppressor gene and is required for correct morphogenesis.
The effects of various lethal mutations were studied when they were present in the hemizygous sta... more The effects of various lethal mutations were studied when they were present in the hemizygous state as sectors in genetic mosaics (gynandro- morphs) of Drosophila melanogaster. Sixty percent of the lethals studied can survive t3 adulthood in combination with normal tissue in mosaics, whereas the remainder cause the death of such mosaic animals. Some of the gynandro- morph-viable lethals appeared
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