Inheritance and linkage of allozymes in seed tissue of whitebark pine

Furnier, Glenn R.; Knowles, Peggy; Aleksiuk, Mary A.; Dancik, Bruce P.

doi:10.1139/g86-088

Cited by 23 publications

(12 citation statements)

References 16 publications

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“…Isozyme analysis of megagametophyte tissue revealed a single intensely stained protein band (ADH2), encoded by a single locus (Adh2), as has been reported for several other pines (29)(30)(31)(32). No ADH activity was observed in extracts of aerobically treated roots, but anaerobic treatment resulted in the induction of ADH2 and a more anodal zone of activity (ADH1), for which the genetic control is unknown.…”

Section: Resultssupporting

confidence: 52%

Pinus banksiana has at least seven expressed alcohol dehydrogenase genes in two linked groups

Perry

Furnier

1996

Proc. Natl. Acad. Sci. U.S.A.

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The alcohol dehydrogenase (Adh) gene family is much more complex in Pinus banksiana than in angiosperms, with at least seven expressed genes organized as two tightly linked clusters. Intron number and position are highly conserved between P. banksiana and angiosperms. Unlike angiosperm Adh genes, numerous duplications, as large as 217 bp, were observed within the noncoding regions of P. banksiana Adh genes and may be a common feature of conifer genes. A high frequency of duplication over a wide range of scales may contribute to the large genome size of conifers.It is well-established that nuclear genomes are much larger in conifers than in angiosperms. In conifers, 2C values (where C is the total amount of DNA in a haploid nucleus) typically range from 20 to 50 pg (1), whereas the corresponding values in angiosperms are typically less than 10 pg and often less than 2 pg (2). However, relatively little is known about the organization of these large conifer genomes. While the proportion of repeated DNA is higher than in angiosperms, there is little relationship between total genomic and repetitive DNA (3). Nuclear rDNA repeat units are much longer in conifers (4-6) and Southern blot analyses of pine DNA with cDNA probes often reveal complex band patterns, suggesting larger gene families and͞or larger genes than in angiosperms (7-10).One of the best characterized plant gene families codes for alcohol dehydrogenases (ADH; EC 1.1.1.1), enzymes that play a central role in anaerobic metabolism (11,12). Most angiosperms express two or three ADH isozymes (13) and Southern blots generally display a corresponding level of complexity (14,15). Sequence data are available for Adh genes of a number of angiosperm species, but relatively little is known about this gene family in conifers, with the only published sequences being three partial Pinus radiata Adh cDNAs, likely representing two loci (7). Typically, two to four ADH isozymes are observed in pines (16), but P. radiata Adh cDNA clones hybridize to many fragments of P. radiata and Pinus taeda DNA (7) and many diverse genomic Adh clones were recovered from these species (17). These observations suggest that the Adh gene family is larger in pines than in angiosperms and͞or that pine Adh genes are larger. We characterized Adh genes in Pinus banksiana Lamb. (jack pine) to examine these hypotheses. Also, due to the successful development of segregating PCR-based gene-specific markers, we were able to examine linkage relationships among Adh loci. METHODSIsozyme Analysis. P. banksiana seeds were germinated on distilled (d) H 2 O-moistened filter paper in Petri dishes at room temperature for 8 days, yielding seedling root lengths of 1-2 cm. The germinating seeds were then given either anaerobic treatment (immersed for 20 hr in dH 2 O under filter paper) or aerobic treatment (seeds remained on moist filter paper).Starch gel electrophoresis (18) was used to examine ADH enzyme activity in the haploid megagametophytes and diploid roots of these seedlings.cDNA Cloning and Char...

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Section: Resultssupporting

confidence: 52%

Pinus banksiana has at least seven expressed alcohol dehydrogenase genes in two linked groups

Perry

Furnier

1996

Proc. Natl. Acad. Sci. U.S.A.

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“…No consistent patterns of linkage disequilibrium have been reported for the loci used in this study in seeds or buds of whitebark pine (Furnier et al 1986;Krakowski et al 2003), so all loci were used in the genetic analysis. The latest version (V 3.1) of the MLTR program (Ritland 2002) was used to analyze the genotypic data.…”

Section: Discussionmentioning

confidence: 76%

Mating system and inbreeding depression in whitebark pine (Pinus albicaulis Engelm.)

Bower

Aitken

2007

Tree Genetics & Genomes

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Mating system and inbreeding depression in quantitative traits of whitebark pine (Pinus albicaulis Engelm.) was determined using isozymes and a seedling common garden experiment. Simultaneous isozyme analysis of embryo and haploid megagametophyes from progeny arrays of families in three distinct geographic regions (Oregon, Montana, and southern British Columbia) was used to estimate parental and progeny inbreeding coefficients, as well as regional and family mean multilocus outcrossing rates (t m ). Quantitative trait family means of seedlings from the same families growing in two temperature treatments in a common garden experiment were regressed on the estimated inbreeding coefficient to determine the presence and magnitude of inbreeding depression. Regional estimates of t m ranged from 0.73 to 0.93, with a mean over all regions of 0.86. Family mean t m values indicated predominant outcrossing; however, some individuals experienced substantial inbreeding. The Oregon region had a significant excess of heterozygotes in the parental generation relative to Hardy-Weinberg equilibrium, while both the Oregon and southern BC regions had a heterozygote deficiency in progeny, suggesting selection against inbred individuals. Biomass in the ambient temperature treatment for the southern BC region was the only trait significantly related to inbreeding coefficient. The mean inbreeding coefficient for this region was 0.25, and based on this relationship, mean predicted biomass would be reduced by 19.6% in this region if inbred individuals are not removed by selection. The estimated outcrossing rate of whitebark pine is slightly lower than most wind-pollinated conifers, and while most individuals are highly outcrossing, some experience substantial inbreeding.

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“…The natural selection might explain these results since those deleterious alleles could be eliminated favoring this type. Linkage between gene markers and deleterious alleles was described by Furnier et al (1986) and Strauss and Conkle (1986) as a reason for segregation distortion. Recessive deleterious alleles linked with gene markers are normally frequent in tree species of crossed pollination (Willians and Savolainen, 1996 Table 5).…”

Section: Segregation Analysismentioning

confidence: 99%

Inheritance and linkage relationships of allozyme variants of ilex paraguariensis St. Hil

Wendt

Sousa

Sebbenn

et al. 2009

Braz. arch. biol. technol.

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Eighteen enzyme systems were examined in Ilex paraguariensis St. Hil. using starch gel electrophoresis. Seven out of 12 active isozyme systems revealed one or more polymorphic loci (PGI, GOT, MR, G-6PDH, MDH, NDH, and 6-PGDH). However, the segregation and linkage analyses were performed only for PGI, GOT, G-6PDH and 6-PGDH systems. Gene segregation at these loci was regular, except for a few trees that showed segregation distortion. Weak linkage disequilibrium between loci was detected, but it was not enough to influence the multilocus estimate.

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Inheritance and linkage of allozymes in seed tissue of whitebark pine

Cited by 23 publications

References 16 publications

Pinus banksiana has at least seven expressed alcohol dehydrogenase genes in two linked groups

Pinus banksiana has at least seven expressed alcohol dehydrogenase genes in two linked groups

Mating system and inbreeding depression in whitebark pine (Pinus albicaulis Engelm.)

Inheritance and linkage relationships of allozyme variants of ilex paraguariensis St. Hil

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