פרסומים

Classical evolutionary theories propose tradeoffs among reproduction, damage repair and lifespan. However, the specific role of the germline in shaping vertebrate aging remains largely unknown. In this study, we used the turquoise killifish (Nothobranchius furzeri) to genetically arrest germline development at discrete stages and examine how different modes of infertility impact life history. We first constructed a comprehensive single-cell gonadal atlas, providing cell-type-specific markers for downstream phenotypic analysis. We show here that germline depletion-but not arresting germline differentiation-enhances damage repair in female killifish. Conversely, germline-depleted males instead showed an extension in lifespan and rejuvenated metabolic functions. Through further transcriptomic analysis, we highlight enrichment of pro-longevity pathways and genes in germline-depleted male killifish and demonstrate functional conservation of how these factors may regulate longevity in germline-depleted Caenorhabditis elegans. Our results, therefore, demonstrate that different germline manipulation paradigms can yield pronounced sexually dimorphic phenotypes, implying alternative responses to classical evolutionary tradeoffs.

The article presents the life and legacy of Rabbi Shimon bar Yochai, one of the most important figures in Judaism. Living in the 2nd century CE, during a period of intense Roman persecution, he was forced to hide in a cave for thirteen years with his son, Rabbi Eleazar, to escape the Romans who wanted to put him to death.

During his stay in the cave, he studied the Torah and received teachings from the prophet Elijah. After emerging, he underwent a profound spiritual transformation, moving from a strictly contemplative vision to a more concrete engagement in community life. He founded a yeshiva in Tekoa and became one of the greatest teachers of his time.

Tradition attributes to him the authorship of the Zohar, the major work of Jewish mysticism. His death is celebrated as a moment of intense joy (Hilloula) during the festival of Lag Ba'omer, the 33rd day of the Omer. According to tradition, on the day of his death, he revealed to his disciples the deepest secrets of the Torah, surrounded by mystical flames.

Even today, thousands of people gather each year in Meron, his burial place, to celebrate his memory by lighting bonfires and dancing, thus perpetuating the tradition of one who is considered a "column of light" connecting the earthly world to the heavenly world.

The Book of Job, like other ancient Near Eastern and biblical texts, makes relatively frequent use of gestures in its discourse. The interpretation of these gestures is often moot. Is a particular gesture physical, which is to say literal, or (also) symbolic, which is to say figurative? How is a gesture’s meaning in a particular context to be divined? Job’s placing his hand over his mouth, for example, is almost universally understood to reflect his self-censure, his silencing of himself. Comparing other instances of this gesture, in Job and elsewhere, leads to a very different nuance of meaning. Silencing oneself is not self-censure but rather an indication of a desire to listen or hear more. This and other gestures in Job will be discussed with attention to the criteria by which meaning, in such instances, is (or is not) determined.

January 2024: Edward L. Greenstein is professor emeritus of Bible at Bar-Ilan University. He has held professorships at the Jewish Theological Seminary and Tel Aviv University and has taught at the Columbia University Graduate School, Yale, Princeton, the Hebrew University, and elsewhere. Recipient of the EMET Prize ("Israel’s Nobel") in the field of Humanities-Biblical Studies, Greenstein has authored and edited numerous works, most prominently Job: A New Translation  (Yale University Press, 2019). He is currently writing commentaries on Job, Lamentations, and Ruth, as well as other books.