RESUMEN: El artículo describe de forma prolija el desarrollo y resultados del V Congreso del Partido Comunista de Cuba celebrado en La Habana eri octubre de 1997. Por el papel hegemónico del Partido Comunista Cubano en el sistema político cubano, las conclusiones del citado congreso pueden ser interpretadas como elementos claves de reflexión en el marco de la situación económica y política de Cuba.ABSTRACT: This article describes in a detailed manner the development and results of the V Congress of the Communist Party of Cuba, which was celebrated in Havanna in October 1997. Due to the crucial role of the Communist Party in Cuba, this article analyses crucial components of the current Cuban political and economic situation.
Some Bacillus-infecting bacteriophages use a peptide-based communication system, termed arbitrium, to coordinate the lysis-lysogeny decision. In this system, the phage produces AimP peptide during the lytic cycle. Once internalized by the host cell, AimP binds to the transcription factor AimR, reducing aimX expression and promoting lysogeny. Although these systems are present in a variety of mobile genetic elements, their role in the phage life cycle has only been characterized in phage phi3T during phage infection. Here, using the B. subtilis SPß prophage, we show that the arbitrium system is also required for normal prophage induction. Deletion of the aimP gene increased phage reproduction, although the aimR deletion significantly reduced the number of phage particles produced after prophage induction. Moreover, our results indicated that AimR is involved in a complex network of regulation and brought forward two new players in the SPß lysis-lysogeny decision system, YopN and the phage repressor YopR. Importantly, these proteins are encoded in an operon, the function of which is conserved across all SPß-like phages encoding the arbitrium system. Finally, we obtained mutant phages in the arbitrium system, which behaved almost identically to the wild-type (WT) phage, indicating that the arbitrium system is not essential in the laboratory but is likely beneficial for phage fitness in nature. In support of this, by possessing a functional arbitrium system, the SPß phage can optimize production of infective particles while also preserving the number of cells that survive after prophage induction, a strategy that increases phage persistence in nature. ; Medical Research Council (UK); BB/N002873/1, BB/V002376/1, and BB/S003835/1 from the Biotechnology and Biological Sciences Research Council (BBSRC, UK); ERC-ADG-2014 proposal no. 670932 Dut-signal (from EU); and Wellcome Trust 201531/Z/16/Z to J.R.P. and grants PID2019-108541GB-I00 from Spanish government (Ministerio de Ciencia e Innovacio ´ n) and PROMETEO/2020/012 ...
13 páginas. contiene información suplementaria ; Some Bacillus-infecting bacteriophages use a peptide-based communication system, termed arbitrium, to coordinate the lysis-lysogeny decision. In this system, the phage produces AimP peptide during the lytic cycle. Once internalized by the host cell, AimP binds to the transcription factor AimR, reducing aimX expression and promoting lysogeny. Although these systems are present in a variety of mobile genetic elements, their role in the phage life cycle has only been characterized in phage phi3T during phage infection. Here, using the B. subtilis SPβ prophage, we show that the arbitrium system is also required for normal prophage induction. Deletion of the aimP gene increased phage reproduction, although the aimR deletion significantly reduced the number of phage particles produced after prophage induction. Moreover, our results indicated that AimR is involved in a complex network of regulation and brought forward two new players in the SPβ lysis-lysogeny decision system, YopN and the phage repressor YopR. Importantly, these proteins are encoded in an operon, the function of which is conserved across all SPβ-like phages encoding the arbitrium system. Finally, we obtained mutant phages in the arbitrium system, which behaved almost identically to the wild-type (WT) phage, indicating that the arbitrium system is not essential in the laboratory but is likely beneficial for phage fitness in nature. In support of this, by possessing a functional arbitrium system, the SPβ phage can optimize production of infective particles while also preserving the number of cells that survive after prophage induction, a strategy that increases phage persistence in nature. ; This work was supported by grants MR/M003876/1, MR/V000772/1, and MR/S00940X/1 from the Medical Research Council (UK); BB/N002873/1, BB/V002376/1, and BB/S003835/1 from the Biotechnology and Biological Sciences Research Council (BBSRC, UK); ERC-ADG-2014 proposal no. 670932Dut-signal (from EU); and Wellcome Trust 201531/Z/16/Z to J.R.P. and grantsPID2019-108541GB-I00 from Spanish government (Ministerio de Ciencia e In-novacio ́n) and PROMETEO/2020/012 from Valencian government to A.M.A.F.-R. is the recipient of fellowship FPU19/00433 from Ministerio de Ciencia,Innovacio ́n y Universidades (Spanish government). Some figures in this manu-script have been created with BioRender.com ; Peer reviewed
