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PATRONUS1 is expressed in meiotic prophase I to regulate centromeric cohesion in Arabidopsis and shows synthetic lethality with OSD1.

Singh DK, Spillane C, Siddiqi I - BMC Plant Biol. (2015)

Bottom Line: Retention of sister centromere cohesion during meiosis I and its dissolution at meiosis II is necessary for balanced chromosome segregation and reduction of chromosome number.We show here that PANS1 protein is found mainly in prophase I of meiosis, with its level declining late in prophase I during diplotene.PANS1 also shows expression in dividing tissues.

View Article: PubMed Central - PubMed

Affiliation: Centre for Cellular and Molecular Biology (CSIR), Uppal Road, Hyderabad, 500007, India. dipesh@ccmb.res.in.

ABSTRACT

Background: Retention of sister centromere cohesion during meiosis I and its dissolution at meiosis II is necessary for balanced chromosome segregation and reduction of chromosome number. PATRONUS1 (PANS1) has recently been proposed to regulate centromere cohesion in Arabidopsis after meiosis I, during interkinesis. pans1 mutants lose centromere cohesion prematurely during interkinesis and segregate randomly at meiosis II. PANS1 protein interacts with components of the Anaphase Promoting Complex/Cyclosome (APC/C).

Results: We show here that PANS1 protein is found mainly in prophase I of meiosis, with its level declining late in prophase I during diplotene. PANS1 also shows expression in dividing tissues. We demonstrate that, in addition to the previously reported premature loss of centromere cohesion during interkinesis, pans1 mutants show partially penetrant defects in centromere cohesion during meiosis I. We also determine that pans1 shows synthetic lethality at the level of the sporophyte, with Omission of Second Division 1 (osd1), which encodes a known inhibitor of the APC/C that is required for cell cycle progression during mitosis, as well as meiosis I and II.

Conclusions: Our results show that PANS1 is expressed mainly in meiosis I where it has an important function and together with previous studies indicate that PANS1 and OSD1 are part of a network linking centromere cohesion and cell cycle progression through control of APC/C activity.

No MeSH data available.


Related in: MedlinePlus

tam1-2 suppresses pans1 sterility. Pollen viability by Alexander staining. a wild type. btam1-2. cpans1-1dtam1-2/pans1-1. Scale bar represent 50 μm
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Fig5: tam1-2 suppresses pans1 sterility. Pollen viability by Alexander staining. a wild type. btam1-2. cpans1-1dtam1-2/pans1-1. Scale bar represent 50 μm

Mentions: To test whether the sterility caused by pans1 is due primarily to defective chromosome segregation during meiosis II, we crossed pans1 with (hemizygous) tardy asynchronous meiosis 1 (tam1) and osd1 mutants in which the majority of meiocytes do not undergo the second meiotic division, leading to the formation of unreduced gametes [23–25]. In the case of the pans1 x tam1 crosses we obtained 9 double mutant plants out of 180 total examined in the F2 (Table 2). All of the pans1 tam1 double mutant plants showed an increase in viable pollen and seed set compared to the pans1 mutant, indicating genetic suppression of the male sterile phenotype of pans1 by a tam1 loss of function allele (Fig. 5; Additional file 1: Figure S4; Table S1). The minority class of inviable pollen (green) observed in pans1 tam1 can be explained by the minority class of meiocytes that undergo meiosis II in tam1 [23, 25].Table 2


PATRONUS1 is expressed in meiotic prophase I to regulate centromeric cohesion in Arabidopsis and shows synthetic lethality with OSD1.

Singh DK, Spillane C, Siddiqi I - BMC Plant Biol. (2015)

tam1-2 suppresses pans1 sterility. Pollen viability by Alexander staining. a wild type. btam1-2. cpans1-1dtam1-2/pans1-1. Scale bar represent 50 μm
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4536785&req=5

Fig5: tam1-2 suppresses pans1 sterility. Pollen viability by Alexander staining. a wild type. btam1-2. cpans1-1dtam1-2/pans1-1. Scale bar represent 50 μm
Mentions: To test whether the sterility caused by pans1 is due primarily to defective chromosome segregation during meiosis II, we crossed pans1 with (hemizygous) tardy asynchronous meiosis 1 (tam1) and osd1 mutants in which the majority of meiocytes do not undergo the second meiotic division, leading to the formation of unreduced gametes [23–25]. In the case of the pans1 x tam1 crosses we obtained 9 double mutant plants out of 180 total examined in the F2 (Table 2). All of the pans1 tam1 double mutant plants showed an increase in viable pollen and seed set compared to the pans1 mutant, indicating genetic suppression of the male sterile phenotype of pans1 by a tam1 loss of function allele (Fig. 5; Additional file 1: Figure S4; Table S1). The minority class of inviable pollen (green) observed in pans1 tam1 can be explained by the minority class of meiocytes that undergo meiosis II in tam1 [23, 25].Table 2

Bottom Line: Retention of sister centromere cohesion during meiosis I and its dissolution at meiosis II is necessary for balanced chromosome segregation and reduction of chromosome number.We show here that PANS1 protein is found mainly in prophase I of meiosis, with its level declining late in prophase I during diplotene.PANS1 also shows expression in dividing tissues.

View Article: PubMed Central - PubMed

Affiliation: Centre for Cellular and Molecular Biology (CSIR), Uppal Road, Hyderabad, 500007, India. dipesh@ccmb.res.in.

ABSTRACT

Background: Retention of sister centromere cohesion during meiosis I and its dissolution at meiosis II is necessary for balanced chromosome segregation and reduction of chromosome number. PATRONUS1 (PANS1) has recently been proposed to regulate centromere cohesion in Arabidopsis after meiosis I, during interkinesis. pans1 mutants lose centromere cohesion prematurely during interkinesis and segregate randomly at meiosis II. PANS1 protein interacts with components of the Anaphase Promoting Complex/Cyclosome (APC/C).

Results: We show here that PANS1 protein is found mainly in prophase I of meiosis, with its level declining late in prophase I during diplotene. PANS1 also shows expression in dividing tissues. We demonstrate that, in addition to the previously reported premature loss of centromere cohesion during interkinesis, pans1 mutants show partially penetrant defects in centromere cohesion during meiosis I. We also determine that pans1 shows synthetic lethality at the level of the sporophyte, with Omission of Second Division 1 (osd1), which encodes a known inhibitor of the APC/C that is required for cell cycle progression during mitosis, as well as meiosis I and II.

Conclusions: Our results show that PANS1 is expressed mainly in meiosis I where it has an important function and together with previous studies indicate that PANS1 and OSD1 are part of a network linking centromere cohesion and cell cycle progression through control of APC/C activity.

No MeSH data available.


Related in: MedlinePlus