bioRxiv Science⌕ Search

Biology subjects

Ben-Shlomo, R.

Publications and source records attributed to Ben-Shlomo, R..

4 recordsLinked to original sources

Meiotic prophase I disruption as a strategy for non-hormonal male contraception using small-molecule inhibitor JQ1

Long-acting non-hormonal male contraceptives are urgently needed but developing strategies that are both effective and reversible presents significant challenges. Here, we investigated the potential of meiotic prophase I blockade as a promising and potentially reversible approach to male contraception. To do this, we utilized (+)-JQ1, a small-molecule inhibitor of the testis-specific protein, BRDT. Daily injections of (+)-JQ1 for three weeks resulted in disrupted spermatogenesis resulting in loss of spermatozoa and an inability to sire pups. While spermatogenic cells repopulated the testis within six weeks post drug cessation, full fertility restoration required a longer recovery period. We attribute this delay in full recovery to persistent issues with the pachytene transcriptional program, which is crucial for meiotic progression and spermatid development. These findings underscore the potential of pharmacological approaches to disrupt meiotic prophase I as a targeted, reversible male contraceptive strategy, providing new insights into developing effective non-hormonal contraceptive approaches.

cell biology↗

The Orshina rhythm in a colonial urochordate: recurrent aging/rejuvenation sequels

When it comes to aging, some colonial invertebrates present disparate patterns from the customary aging phenomenon in unitary organisms, where a single senescence phenomenon along ontogeny culminates in their inevitable deaths. Here we studied aging processes in 81 colonies of the marine urochordate Botryllus schlosseri each followed from birth to death (over 720 days). The colonies were divided between three life history strategies, each distinct from the others based on the existence/absence of colonial fission: NF (no fission), FA (fission develops after the colony reaches maximal size), and FB (fission develops before the colony reaches maximal size). Results revealed that sexual reproductive statuses (hermaphroditism and male only settings), colonial vigorousness and sizes, represent coinciding and repeated rhythms of one or more emerged life/death astogenic segments on the whole-genet level, each is termed as Orshina, and the sum of all segments as the Orshina rhythm. Each Orshina segment lasts about three months (containing ca. 13 blastogenic cycles), ends by either the colonial death or rejuvenation, and manipulated by absence/existing of fission events in NF/FA/FB strategies. These findings indicate that reproduction, life span, death, rejuvenation and fission events are important scheduled biological components in the constructed Orshina rhythm, a novel aging phenomenon.

evolutionary biology↗

The dynamics of speciation in the gall-forming aphid Geoica spp. within and among Pistacia host tree species

Trees of the genus Pistacia serve as obligate hosts for gall-forming aphids (Hemiptera, Aphididae, Fordini). Each aphid species induces a characteristic gall on a single Pistacia host species. The genus Geoica (Fordini) induce similar spherical closed galls on the lower side of the leaflets midvein, on different Pistacia species. Two species of Pistacia trees that harbor Geoica galls grow naturally in Israel: P. palaestina and P. atlantica. We analyzed the phylogeny and the genetic structure of the Geoica species complex in Israel, and assessed the genetic differentiation and the level of host plant specificity of the aphids between P. atlantica and P. palaestina. We found that the splitting of the genus between P. atlantica and P. palaestina is estimated to have occurred 24-25 Ma (the Oligocene/Miocene boundary). Five different haplotypes suggesting five different species have been further speciating among Geoica spp., galling on P. atlantica, and an additional three species, on P. palaestina. Accession Numbers (COI sequences)MW452548 - Pp-Q-7d-Gamla - Haplotype-VI MW452549 - Pp-Q-10b-Gamla - Haplotype-VII MW452550 - Pp-A-1a-Mezar - Haplotype-VII MW452551 - Pp-S-6c-Sasa - Haplotype-VI MW452552 - Pp-New Hermon-2-5 - Haplotype-VIII MW452553 - Pa-Q-10a-II Gamla - Haplotype-IV MW452554 - Pa-Q-5d Gamla - Haplotype-II MW452555 - Pa-A-2f Mezar - Haplotype-IV MW452556 - Pa-E-13 Anafa - Haplotype-III MW452557 - Pa-K-10a Adolam - Haplotype-IV MW452558 - Pa-K-3a Adolam - Haplotype-II MW452559 - Pa-N-2a Nizana - Haplotype-I MW452560 - Pa-Z-1-3 Hazeva - Haplotype-I MW452561 - Pa-SL-3-3 Jordan-Sela - Haplotype-V

genetics↗

Global Age-Specific Patterns of Cyclic Gene Expression Revealed by Tunicate Transcriptome Atlas

Expression levels of circadian clock genes, which regulate 24-hour rhythms of behavior and physiology, have been shown to change with age. However, a study holistically linking aging and circadian gene expression is missing. Using the colonial chordate Botryllus schlosseri, we combined transcriptome sequencing and stem cell-mediated aging phenomena to test how circadian gene expression changes with age. This revealed that B. schlosseri clock and clock-controlled genes oscillate organism-wide, with daily, age-specific amplitudes and frequencies. These age-related, circadian patterns persist at the tissue level, where dramatic variations in cyclic gene expression of tissue profiles link to morphological and cellular aging phenotypes. Similar cyclical expression differences were found in hundreds of pathways associated with known hallmarks of aging, as well as pathways that were not previously linked to aging. The atlas we developed points to alterations in circadian gene expression as a key regulator of aging. One Sentence SummaryThe Ticking Clock: Systemic changes in circadian gene expression correlates with wide-ranging phenotypes of aging

developmental biology↗