[ { "id": "authors:nn3ts-z5j70", "collection": "authors", "collection_id": "nn3ts-z5j70", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:DOBpnas39b", "type": "article", "title": "Discovery of a predicted gene arrangement in Drosophila azteca", "author": [ { "family_name": "Dobzhansky", "given_name": "Th.", "clpid": "Dobzhansky-Th" } ], "abstract": "A method which under certain conditions permits prediction of as yet undiscovered gene arrangements was described a few years ago.(1,2) Its essence is as follows. If an inversion transforms the gene arrangement ABCDEFGH into AEDCBFGH, a second inversion taking place in the altered chromosome may be of the overlapping type, that is one of the breaks of the second inversion may lie within and the second break outside the limits of the first inversion. Thus the arrangement AEDCBFGH becomes AEDGFBCH. If the first and the third of these arrangements are known, one can postulate the existence of AEDCBFGH as a necessary intermediate step. If a family of gene arrangements related as overlapping inversions is known, a phylogenetic scheme indicating the lines of descent within this family may be drawn. Occasionally such phylogenetic schemes involve hypothetical links constructed with the aid of the method just outlined. The purpose of the present note is to record an instance of the discovery of such an hypothetical link, and certain related facts.", "doi": "10.1073/pnas.27.1.47", "issn": "0027-8424", "publisher": "National Academy of Sciences", "publication": "Proceedings of the National Academy of Sciences of the United States of America", "publication_date": "1941-01-01", "series_number": "1", "volume": "27", "issue": "1", "pages": "47-50" }, { "id": "authors:ekync-68d66", "collection": "authors", "collection_id": "ekync-68d66", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:DOBpnas39a", "type": "article", "title": "Microgeographic variation in Drosophila pseudoobscura", "author": [ { "family_name": "Dobzhansky", "given_name": "Th.", "clpid": "Dobzhansky-Th" } ], "abstract": "Studies of recent years have revealed a prodigious amount of variability in the gene arrangement in the chromosomes of several species of Drosophila. In natural populations of D. pseudooobscura the third chromosome is more variable than the rest; eighteen structural types, related to each other mostly as overlapping inversions, have been found in this chromosome alone.(1)", "doi": "10.1073/pnas.25.7.311", "issn": "0027-8424", "publisher": "National Academy of Sciences", "publication": "Proceedings of the National Academy of Sciences of the United States of America", "publication_date": "1939-07-01", "series_number": "7", "volume": "25", "issue": "7", "pages": "311-314" }, { "id": "authors:6h3fm-kxa48", "collection": "authors", "collection_id": "6h3fm-kxa48", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200409-143454994", "type": "article", "title": "A Possible Method for Locating Favorable Genes in Maize", "author": [ { "family_name": "Dobzhansky", "given_name": "Th.", "clpid": "Dobzhansky-Th" }, { "family_name": "Rhoades", "given_name": "M. M.", "clpid": "Rhoades-M-M" } ], "abstract": "Present-day methods of corn improvement involve the isolation of inbred lines through self-fertilization and selection. These inbred strains are subsequently intercrossed and some, though not all, hybrid combinations are superior in vigor to the open-pollinated varieties from which the inbred lines were derived. Practically all crosses are greatly superior to the vigor of the inbred parents. The theoretical foundations for the increased vigor obtained by these empirical methods have never been completely established. The assumption is that open-pollinated varieties of corn are heterozygous for many pairs of genes, the recessive alleles of which have in general less favorable effects upon viability and vigor than their dominant alleles. Different varieties and different individuals of the same variety may carry different recessive genes.", "doi": "10.2134/agronj1938.00021962003000080005x", "issn": "0002-1962", "publisher": "Wiley", "publication": "Agronomy Journal", "publication_date": "1938-08", "series_number": "8", "volume": "30", "issue": "8", "pages": "668-675" }, { "id": "authors:s4va2-jtg07", "collection": "authors", "collection_id": "s4va2-jtg07", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:STUpnas36", "type": "article", "title": "Inversions in the third chromosome of wild races of Drosophila pseudoobscura, and their use in the study of the history of the species", "author": [ { "family_name": "Sturtevant", "given_name": "A. H.", "clpid": "Sturtevant-A-H" }, { "family_name": "Dobzhansky", "given_name": "Th.", "clpid": "Dobzhansky-Th" } ], "abstract": "Genetic studies showed several years ago that the third chromosomes of wild strains of Drosophila pseudoobscura often carry suppressors of crossing-over. The salivary gland chromosome technique has made it possible to demonstrate not only that these are inverted sections, but also that there are many different inversions present in wild populations inhabiting different geographical regions. So far we have found at least fourteen different gene-sequences in wild stocks, and have found that in most geographical regions several sequences are present, though no single sequence appears to occur throughout the range of the species. There are a number of problems raised by these facts, most of which need further study; the present account is to be regarded only as a preliminary note.", "doi": "10.1073/pnas.22.7.448", "pmcid": "PMC1076803", "issn": "0027-8424", "publisher": "National Academy of Sciences", "publication": "Proceedings of the National Academy of Sciences of the United States of America", "publication_date": "1936-07", "series_number": "7", "volume": "22", "issue": "7", "pages": "448-450" }, { "id": "authors:vsq91-em661", "collection": "authors", "collection_id": "vsq91-em661", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:DOBpnas35b", "type": "article", "title": "Further Data on Material Effects in Drosophila Pseudo\u00f6bscura Hybrids", "author": [ { "family_name": "Dobzhansky", "given_name": "Th.", "clpid": "Dobzhansky-Th" }, { "family_name": "Sturtevant", "given_name": "A. H.", "clpid": "Sturtevant-A-H" } ], "abstract": "Race B females of Drosophila pseudo\u00f6bscura crossed to race A males produce sterile F1 hybrid males having visibly small testes. The reciprocal cross, A \u2640 X B \u2642, produces in F1 sterile males that have testes of normal size. One of us(1) has shown that this difference between the reciprocal crosses is due to a maternal effect. Before fertilization, the cytoplasm of the eggs deposited by race B females is so influenced by the chromosomes present in it, that an interaction between this cytoplasm and the autosomes of race A (introduced by the spermatozoon) results in the development of small testes in males arising from such eggs.", "doi": "10.1073/pnas.21.10.566", "pmcid": "PMC1076660", "issn": "0027-8424", "publisher": "National Academy of Sciences", "publication": "Proceedings of the National Academy of Sciences of the United States of America", "publication_date": "1935-10", "series_number": "10", "volume": "21", "issue": "10", "pages": "566-570" }, { "id": "authors:ma6n8-6dd24", "collection": "authors", "collection_id": "ma6n8-6dd24", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:DOBpnas35a", "type": "article", "title": "Maternal effect as a cause of the difference between the reciprocal crosses in Drosophila pseudoobscura", "author": [ { "family_name": "Dobzhansky", "given_name": "Th.", "clpid": "Dobzhansky-Th" } ], "abstract": "Reciprocal crosses not infrequently produce different results; this fact is sometimes quoted as an evidence for cytoplasmatic inheritance, although the fallacy of the argument has been repeatedly pointed out. It is to be granted, however, that the cause of the difference between reciprocal crosses has not been adequately analyzed in most cases. An approximation toward such an analysis is now possible in the hybrids between race A and race B of Drosophila pseudoobscura Frolowa.", "doi": "10.1073/pnas.21.7.443", "issn": "0027-8424", "publisher": "National Academy of Sciences", "publication": "Proceedings of the National Academy of Sciences of the United States of America", "publication_date": "1935-07-01", "series_number": "7", "volume": "21", "issue": "7", "pages": "443-446" }, { "id": "authors:e7h60-fwh27", "collection": "authors", "collection_id": "e7h60-fwh27", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170404-073558538", "type": "article", "title": "The mutant \"proboscipedia\" in Drosophila melanogaster \u2014 A case of hereditary homo\u00f6sis", "author": [ { "family_name": "Bridges", "given_name": "Calvin B.", "clpid": "Bridges-C-B" }, { "family_name": "Dobzhansky", "given_name": "Th.", "clpid": "Dobzhansky-Th" } ], "abstract": "The recessive mutant \"proboscipedia\", found by Bridges April 27, 1931, has its locus in the third chromosome at approximately 5.3 units to the right of Dichaete, or at 45.7.\n\nIn proboscipedia the oral lobes are converted into a labium-like organ, which also resembles a pair of antenna-like or tarsus-like appendages. This change, as well as the modifications of the labrum, maxillae, maxillary palpi, and other structures give to the mouth parts of proboscipedia a resemblance to those of the biting type found in insects of lower orders.\n\nThe four-fold resemblance of the modified oral lobes in proboscipedia to the labrum, the maxillary palpi, the antenae and the tarsi is comprehensible in view of the homology of these three head-appendages with each other and with the walking legs.", "doi": "10.1007/BF01380474", "issn": "0043-5546", "publisher": "Springer", "publication": "Wilhelm Roux' Archiv f\u00fcr Entwicklungsmechanik der Organismen", "publication_date": "1933-12", "series_number": "4", "volume": "127", "issue": "4", "pages": "575-590" }, { "id": "authors:p46k3-gqz47", "collection": "authors", "collection_id": "p46k3-gqz47", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:DOBpnas33b", "type": "article", "title": "Role of the autosomes in the Drosophila pseudoobscura hybrids", "author": [ { "family_name": "Dobzhansky", "given_name": "Th.", "clpid": "Dobzhansky-Th" } ], "abstract": "Lancefield(1) discovered that the species Drosophila pseudoobscura consists of two races, called race A and race B, respectively. Completely sterile males and partially fertile females appear in the offspring if the races are intercrossed. Males coming from the cross, B\u2640 X A\u2642, have rudimentary testes that are smaller in size than the testes of normal males. Testes of the A\u2640 X B\u2642 hybrid males are normal in size but incapable of producing functional sperm.", "issn": "0027-8424", "publisher": "National Academy of Sciences", "publication": "Proceedings of the National Academy of Sciences of the United States of America", "publication_date": "1933-11-01", "series_number": "11", "volume": "19", "issue": "11", "pages": "950-953" }, { "id": "authors:0f346-m9t36", "collection": "authors", "collection_id": "0f346-m9t36", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:DOBpnas33a", "type": "article", "title": "On the sterility of the interracial hybrids in Drosophila pseudoobscura", "author": [ { "family_name": "Dobzhansky", "given_name": "Th.", "clpid": "Dobzhansky-Th" } ], "abstract": "Offspring from interspecific crosses are frequently equal or superior to their parents in somatic vigor, and are, nevertheless, partially or completely sterile. The sterility is due to a disturbance in the process of gametogenesis usually involving a more or less complete lack of chromosome pairing at meiosis. The known instances of interspecific sterility fall into two groups. To the first group belong cases described by Karpechenko,(1) Clausen,(2) Tschermak and Bleier(3) and many others, who have found that the doubling of the chromosome complement of sterile hybrids results in the appearance of fertile allotetraploids showing a more or less complete chromosome pairing. To the second group belongs the case of the interracial hybrids in Drosophila pseudoobscura. As shown below, the doubling of the chromosomes does not influence here either the lack of chromosome pairing or sterility.", "issn": "0027-8424", "publisher": "National Academy of Sciences", "publication": "Proceedings of the National Academy of Sciences of the United States of America", "publication_date": "1933-04-01", "series_number": "4", "volume": "19", "issue": "4", "pages": "397-403" }, { "id": "authors:aqhs6-k6h48", "collection": "authors", "collection_id": "aqhs6-k6h48", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170404-073201187", "type": "article", "title": "Genes that affect early developmental stages of Drosophila melanogaster", "author": [ { "family_name": "Dobzhansky", "given_name": "Th.", "clpid": "Dobzhansky-Th" }, { "family_name": "Duncan", "given_name": "F. N.", "clpid": "Duncan-F-N" } ], "abstract": "[no abstract]", "doi": "10.1007/BF00596558", "issn": "0043-5546", "publisher": "Springer", "publication": "Wilhelm Roux' Archiv f\u00fcr Entwicklungsmechanik der Organismen", "publication_date": "1933-03", "series_number": "1", "volume": "130", "issue": "1", "pages": "109-130" }, { "id": "authors:akq13-72316", "collection": "authors", "collection_id": "akq13-72316", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:DOBpnas31", "type": "article", "title": "Evidence for multiple sex factors in the X-chromosome of Drosophila melanogaster", "author": [ { "family_name": "Dobzhansky", "given_name": "Th.", "clpid": "Dobzhansky-Th" }, { "family_name": "Schultz", "given_name": "Jack", "clpid": "Schultz-J" } ], "abstract": "The data presented here permit a decision between two alternative hypotheses regarding sex determination in Drosophila melanogaster. Bridges(1,2,3) has shown that the sex of an individual in this form is determined by a relation between the number of the X-chromosomes and that of the autosomes. From his studies of a variety of sex types (table 1), he has concluded that the X-chromosome turns the course of development toward femaleness, the autosomes toward maleness.", "doi": "10.1073/pnas.17.9.513", "issn": "0027-8424", "publisher": "National Academy of Sciences", "publication": "Proceedings of the National Academy of Sciences of the United States of America", "publication_date": "1931-09-01", "series_number": "9", "volume": "17", "issue": "9", "pages": "513-518" }, { "id": "authors:d38xp-13009", "collection": "authors", "collection_id": "d38xp-13009", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170404-073934825", "type": "article", "title": "Interaction between female and male parts in gynandromorphs of Drosophila simulans", "author": [ { "family_name": "Dobzhansky", "given_name": "T.", "clpid": "Dobzhansky-Th" } ], "abstract": "[no abstract]", "doi": "10.1007/BF01380651", "issn": "0043-5546", "publisher": "Springer", "publication": "Wilhelm Roux' Archiv f\u00fcr Entwicklungsmechanik der Organismen", "publication_date": "1931-09", "series_number": "3-4", "volume": "123", "issue": "3-4", "pages": "719-746" }, { "id": "authors:nvkfb-wb918", "collection": "authors", "collection_id": "nvkfb-wb918", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:STUpnas30", "type": "article", "title": "Reciprocal translocations in Drosophila and their bearing on Oenothera cytology and genetics", "author": [ { "family_name": "Sturtevant", "given_name": "A. H.", "clpid": "Sturtevant-A-H" }, { "family_name": "Dobzhansky", "given_name": "T.", "clpid": "Dobzhansky-Th" } ], "abstract": "Belling(1) suggested that the chromosome rings found in Oenothera by Cleland(2) and others are to be explained as resulting from exchanges of ends between non-homologous chromosomes, so that one chromosome of a given complex is homologous at one end to one chromosome of a second complex, and at the other end to a different chromosome of the second complex. Hlkansson(3) and Darlington(4) have elaborated this view. In a recent issue of this JOURNAL Cleland and Blakeslee(5) have carried the analysis through in detail, showing that it gives self-consistent results. It enables one to predict the configurations of untried combinations, and is to a certain extent in agreement with the genetic data of Renner(6) and Oehlkers.(7)", "doi": "10.1073/pnas.16.8.533", "pmcid": "PMC526684", "issn": "0027-8424", "publisher": "National Academy of Sciences", "publication": "Proceedings of the National Academy of Sciences of the United States of America", "publication_date": "1930-08", "series_number": "8", "volume": "16", "issue": "8", "pages": "533-536" }, { "id": "authors:5nx7f-ecz88", "collection": "authors", "collection_id": "5nx7f-ecz88", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:DOBpnas29", "type": "article", "title": "A homozygous translocation in Drosophila melanogaster", "author": [ { "family_name": "Dobzhansky", "given_name": "Th.", "clpid": "Dobzhansky-Th" } ], "abstract": "Five cases of translocation involving the third and the fourth chromosomes of Drosophila melanogaster have been found in the progeny of flies treated by x-rays. The flies carrying a given translocation seem to be perfectly normal in their appearance, but, when tested genetically, they show linkage of genes belonging to the third with genes belonging to the fourth linkage group.", "issn": "0027-8424", "publisher": "National Academy of Sciences", "publication": "Proceedings of the National Academy of Sciences of the United States of America", "publication_date": "1929-08-01", "series_number": "8", "volume": "15", "issue": "8", "pages": "633-638" }, { "id": "authors:h21sc-wjc88", "collection": "authors", "collection_id": "h21sc-wjc88", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170404-074151810", "type": "article", "title": "The influence of the quantity and quality of chromosomal material on the size of the cells in drosophila melanogaster", "author": [ { "family_name": "Dobzhansky", "given_name": "Th.", "clpid": "Dobzhansky-Th" } ], "abstract": "1. The small bristles on the surface of the wing ofDrosophila correspond each to a single cell. This fact makes possible the measurement of the size of the cells by counting the number of bristles within a known area of the wing surface.\n\n2. Comparison of the cell size in male, female, superfemale, supermale, intersex and triploid female showed that the size of the cells increases with the increase of the total volume of the chromosomes contained in their nuclei.\n\n3. The presence or absence of the Y-chromosome does not affect the size of the cells in spite of the considerable volume of the chromosome.\n\n4. The loss of one fourth chromosome reduces the size of the cells considerably in spite of the smallness of the volume of this chromosome.\n\n5. The mutant gene miniature alters the size of the cells strikingly. The epidermal cells of the wing membrane are apparent in miniature during the whole imaginal life of the fly; in wild-type and in all other mutants studied the epidermal cells degenerate soon after the emergence of the fly from the pupa.\n\n6. The size of the cells in different races of the same species is determined by the quality as well as by the quantity of the chromosomal material contained in their nuclei.", "doi": "10.1007/BF02078996", "issn": "0043-5546", "publisher": "Springer", "publication": "Wilhelm Roux' Archiv f\u00fcr Entwicklungsmechanik der Organismen", "publication_date": "1929-04", "series_number": "3", "volume": "115", "issue": "3", "pages": "363-379" }, { "id": "authors:x6h55-8qv68", "collection": "authors", "collection_id": "x6h55-8qv68", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:DOBpnas28", "type": "article", "title": "The effect of temperature on the viability of superfemales in Drosophila melanogaster", "author": [ { "family_name": "Dobzhansky", "given_name": "Th.", "clpid": "Dobzhansky-Th" } ], "abstract": "The superfemale is an individual having three X-chromosomes and two sets of autosomes. It has also many external characteristics by means of which it can be easily distinguished both from the normal sexes and from other sexual forms, i.e., intersexes and supermales. The superfemales arise in several kinds of genetical experiments concerned with abnormal chromosomal situations, such as in the progeny of the attached X-chromosome female, of the triploid female and in cases of non-disjunction of the X-chromosomes. But the frequency of superfemales found in cultured is always very much below that which might be expected theoretically on the basis of a knowledge of the genetic situation in a given case. Therefore, the superfemale can be considered as a typical semilethal form, which only relatively rarely reaches the imago stage.", "doi": "10.1073/pnas.14.8.671", "issn": "0027-8424", "publisher": "National Academy of Sciences", "publication": "Proceedings of the National Academy of Sciences of the United States of America", "publication_date": "1928-08-01", "series_number": "8", "volume": "14", "issue": "8", "pages": "671-675" } ]