Two portable recombination enhancers direct donor choice in fission yeast heterochromatin

TY - JOUR

T1 - Two portable recombination enhancers direct donor choice in fission yeast heterochromatin

AU - Jakociunas, Tadas

AU - Holm, Lærke Rebekka

AU - Hansen, Janne Verhein

AU - Trusina, Ala

AU - Thon, Genevieve

PY - 2013/10

Y1 - 2013/10

N2 - Mating-type switching in fission yeast results from gene conversions of the active mat1 locus by heterochromatic donors. mat1 is preferentially converted by mat2-P in M cells and by mat3-M in P cells. Here, we report that donor choice is governed by two portable recombination enhancers capable of promoting use of their adjacent cassette even when they are transposed to an ectopic location within the mat2-mat3 heterochromatic domain. Cells whose silent cassettes are swapped to mat2-M mat3-P switch mating-type poorly due to a defect in directionality but cells whose recombination enhancers were transposed together with the cassette contents switched like wild type. Trans-acting mutations that impair directionality affected the wild-type and swapped cassettes in identical ways when the recombination enhancers were transposed together with their cognate cassette, showing essential regulatory steps occur through the recombination enhancers. Our observations lead to a model where heterochromatin biases competitions between the two recombination enhancers to achieve directionality.

AB - Mating-type switching in fission yeast results from gene conversions of the active mat1 locus by heterochromatic donors. mat1 is preferentially converted by mat2-P in M cells and by mat3-M in P cells. Here, we report that donor choice is governed by two portable recombination enhancers capable of promoting use of their adjacent cassette even when they are transposed to an ectopic location within the mat2-mat3 heterochromatic domain. Cells whose silent cassettes are swapped to mat2-M mat3-P switch mating-type poorly due to a defect in directionality but cells whose recombination enhancers were transposed together with the cassette contents switched like wild type. Trans-acting mutations that impair directionality affected the wild-type and swapped cassettes in identical ways when the recombination enhancers were transposed together with their cognate cassette, showing essential regulatory steps occur through the recombination enhancers. Our observations lead to a model where heterochromatin biases competitions between the two recombination enhancers to achieve directionality.

U2 - 10.1371/journal.pgen.1003762

DO - 10.1371/journal.pgen.1003762

M3 - Journal article

C2 - 24204285

SN - 1553-7390

VL - 9

JO - P L o S Genetics

JF - P L o S Genetics

IS - 10

M1 - e1003762

ER -