Transient Replication in Specialized Cells Favors Conjugative Transfer of a Selfish DNA Element

AbstractBacterial evolution is driven to a large extent by horizontal gene transfer (HGT) – the processes that distribute genetic material between species rather than by vertical descent. HGT is mostly mediated by an assortment of different selfish DNA elements, several of which have been characterized in great molecular detail. In contrast, very little is known on adaptive features optimizing horizontal fitness. By using single DNA molecule detection and time-lapse microscopy, we analyze here the fate of an integrative and conjugative element (ICE) in individual cells of the bacteriumPseudomonas putida. We uncover how the ICE excises and irregularly replicates, exclusively in a sub-set of specialized host cells. As postulated, ICE replication is dependent on its origin of transfer and its DNA relaxase. Rather than being required for ICE maintenance, however, we find that ICE replication serves more effective conjugation to recipient cells, providing selectable benefit to its horizontal transfer.

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Time-Lapse Microscopy Portrays Microsporidia Invading Host Cells

Microbe Magazine ◽

10.1128/microbe.3.361.1 ◽

2008 ◽

Vol 3 (8) ◽

pp. 361-362

Author(s):

David Holzman

Keyword(s):

Time Lapse ◽

Host Cells ◽

Time Lapse Microscopy

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Multi-generational Analysis and Manipulation of Chromosomes in a Polyploid Cyanobacterium

10.1101/661256 ◽

2019 ◽

Cited By ~ 2

Author(s):

Kristin A. Moore ◽

Jian Wei Tay ◽

Jeffrey C. Cameron

Keyword(s):

Dna Replication ◽

Cell Growth ◽

Photosynthetic Bacteria ◽

Bacterial Species ◽

Genetic Material ◽

Time Lapse ◽

Time Lapse Microscopy ◽

Life On Earth ◽

Microbial Dna

ABSTRACTFaithful inheritance of genetic material from one generation to the next is an essential process for all life on earth. Much of what is known about microbial DNA replication and inheritance has been learned from a small number of bacterial species that share many common traits. Whether these pathways are conserved across the great diversity of the microbiome remains unclear. To address this question, we studied chromosome dynamics in a polyploid photosynthetic bacteria using single cell, time-lapse microscopy over multi-generation lineages in conjunction with inducible CRISPR-interference and fluorescent chromosome labeling. With this method we demonstrated the long-term consequences of manipulating parameters such as cell growth, cell division, and DNA replication and segregation on chromosome regulation in a polyploid bacterial species. We find that these bacteria are surprisingly resilient to chromosome disruption resulting in continued cell growth when DNA replication is inhibited and even in the complete absence of chromosomes.

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Experience of using time-lapse microscopy in IVF and ICSI programs

Medical alphabet ◽

10.33667/2078-5631-2020-16-47-50 ◽

2020 ◽

pp. 47-50

Author(s):

N. V. Saraeva ◽

N. V. Spiridonova ◽

M. T. Tugushev ◽

O. V. Shurygina ◽

A. I. Sinitsyna

Keyword(s):

Pregnancy Rate ◽

Embryo Transfer ◽

Selection Procedure ◽

Time Lapse ◽

Single Embryo Transfer ◽

Main Group ◽

Clinical Pregnancy ◽

Control Group ◽

Time Lapse Microscopy

In order to increase the pregnancy rate in the assisted reproductive technology, the selection of one embryo with the highest implantation potential it is very important. Time-lapse microscopy (TLM) is a tool for selecting quality embryos for transfer. This study aimed to assess the benefits of single-embryo transfer of autologous oocytes performed on day 5 of embryo incubation in a TLM-equipped system in IVF and ICSI programs. Single-embryo transfer following incubation in a TLM-equipped incubator was performed in 282 patients, who formed the main group; the control group consisted of 461 patients undergoing single-embryo transfer following a traditional culture and embryo selection procedure. We assessed the quality of transferred embryos, the rates of clinical pregnancy and delivery. The groups did not differ in the ratio of IVF and ICSI cycles, average age, and infertility factor. The proportion of excellent quality embryos for transfer was 77.0% in the main group and 65.1% in the control group (p = 0.001). In the subgroup with receiving eight and less oocytes we noted the tendency of receiving more quality embryos in the main group (р = 0.052). In the subgroup of nine and more oocytes the quality of the transferred embryos did not differ between two groups. The clinical pregnancy rate was 60.2% in the main group and 52.9% in the control group (p = 0.057). The delivery rate was 45.0% in the main group and 39.9% in the control group (p > 0.050).

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