bims-micesi 2023-12-31 papers

Issue of 2023–12–31
two papers selected by
Valentina Piano, Uniklinik Köln

FEBS Open Bio. 2023 Dec 27.

SETDB2 interacts with BUBR1 to induce accurate chromosome segregation independently of its histone methyltransferase activity.

Yanhong Tu, Haomiao Zhang, Jialin Xia, Yu Zhao, Ruifang Yang, Jing Feng, Xueyun Ma, Jing Li.

SETDB2 is a H3K9 histone methyltransferase required for accurate chromosome segregation. Its H3K9 histone methyltransferase activity was reported to be associated with chromosomes during metaphase. Here, we confirm that SETDB2 is required for mitosis and accurate chromosome segregation. However, these functions are independent of its histone methyltransferase activity. Further analysis showed that SETDB2 can interact with BUBR1, and is required for CDC20 binding to BUBR1 and APC/C complex and CYCLIN B1 degradation. The ability of SETDB2 to regulate the binding of CDC20 to BUBR1 or APC/C complex, and stabilization of CYCLIN B1 are also independent of its histone methyltransferase activity. These results suggest that SETDB2 interacts with BUBR1 to promote binding of CDC20 to BUBR1 and APC3, then degrades CYCLIN B1 to ensure accurate chromosome segregation and mitosis, independently of its histone methyltransferase activity.

Keywords: APC/C; BUBR1; CDC20; SETDB2; chromosome segregation; mitosis

DOI: https://doi.org/10.1002/2211-5463.13761

Comp Cytogenet. 2023 ;17 273-281

Metaphase chromosomes of five Neotropical species of the genus Drosophila (Diptera, Drosophilidae).

Doris Vela, Erika Villavicencio.

The mitotic metaphases of five Andean species of genus Drosophila are described for the first time. The evolutionary and interspecific genetic relationships within three Neotropical Drosophila species groups are analyzed. The diploid chromosome number for each species is as follows: D.cashapamba Céspedes et Rafael, 2012 2n = 6 (2V, 1J) (X = J, Y = R), D.ecuatoriana Vela et Rafael, 2004 2n = 10 (3R, 2V) (X = V, Y = R), D.ninarumi Vela et Rafael, 2005 2n = 10 (3R, 1V, 1D) (X = V, Y = R), D.urcu Vela et Rafael, 2005 2n = 12 (4R, 2V) (X = V, Y = R), D.valenteae Llangarí-Arizo et Rafael, 2018 2n = 8 (3R, 1J) (X = J, Y = R).

Keywords: Andean; Drosophila chromosomes; guarani; mesophragmatica; metaphase; tripunctata

DOI: https://doi.org/10.3897/compcytogen.17.108265