Oct 22, 1991

More is not better: brood size and population growth in a self-fertilizing nematode

Proceedings. Biological Sciences
J Hodgkin, T M Barnes

Abstract

The normal form of the nematode Caenorhabditis elegans is a self-fertilizing hermaphrodite, which produces from the same germ-line tissue first a limited number of sperm and then a larger number of oocytes. Self-progeny brood sizes are determined by the number of sperm, and most of the oocytes remain unfertilized. Therefore it might seem selectively advantageous to increase the number of sperm, and hence the size of the brood. A mutation that leads to a 50% increase in sperm production allows a comparison of population growth rates between the wild type (mean brood 327 progeny) and the mutant (mean brood 499 progeny). Wild-type populations grow faster, as measured by food consumption, indicating that increased brood size is not advantageous. The mutant appears to be at a disadvantage because the additional spermatogenesis leads to a delay in the onset of oogenesis, and hence to an increase in the minimum generation time. In support of the notion of an optimal brood size, it was found that different natural isolates of this species have self-fertilities similar to that of the standard laboratory strain, in the range 250-350 progeny per worm.

  • References9
  • Citations81

Citations

Mentioned in this Paper

Fertility
Caenorhabditis elegans
Reproduction
Spermatogenesis
Caenorhabditis
Oocytes
Mutant
Hermaphroditism
Intersexuality
Polyspermic Fertilization

Trending Feeds

COVID-19

Coronaviruses encompass a large family of viruses that cause the common cold as well as more serious diseases, such as the ongoing outbreak of coronavirus disease 2019 (COVID-19; formally known as 2019-nCoV). Coronaviruses can spread from animals to humans; symptoms include fever, cough, shortness of breath, and breathing difficulties; in more severe cases, infection can lead to death. This feed covers recent research on COVID-19.

Coronavirus Protein Structures

Deciphering and comparing the proteins of different coronaviruses forms a basis for understanding SARS-CoV-2 evolution and virus-receptor interactions. This feed follows studies analyzing the structures of coronavirus proteins, thereby revealing potential drug target sites.

DDX3X Syndrome

DDX3X syndrome is caused by a spontaneous mutation at conception that primarily affects girls due to its location on the X-chromosome. DDX3X syndrome has been linked to intellectual disabilities, seizures, autism, low muscle tone, brain abnormalities, and slower physical developments. Here is the latest research.

ALS: Stress Granules

Amyotrophic Lateral Sclerosis (ALS) is a neurodegenerative disease characterized by cytoplasmic protein aggregates within motor neurons. TDP-43 is an ALS-linked protein that is known to regulate splicing and storage of specific mRNAs into stress granules, which have been implicated in formation of ALS protein aggregates. Here is the latest research.

Fusion Oncoproteins in Childhood Cancers

This feed explores the function of fusion oncoproteins in specific childhood cancers, including those from racial/ethnic minority and underserved groups, and to provide preclinical assessment of potential therapeutics and how fusion oncoproteins influence gene expression to perturb normal cellular programs to block lineage differentiation and development

Applications of Molecular Barcoding

The concept of molecular barcoding is that each original DNA or RNA molecule is attached to a unique sequence barcode. Sequence reads having different barcodes represent different original molecules, while sequence reads having the same barcode are results of PCR duplication from one original molecule. Discover the latest research on molecular barcoding here.

Regulation of Vocal-Motor Plasticity

Dopaminergic projections to the basal ganglia and nucleus accumbens shape the learning and plasticity of motivated behaviors across species including the regulation of vocal-motor plasticity and performance in songbirds. Discover the latest research on the regulation of vocal-motor plasticity here.

Mitotic-exit networks with cytokinesis

Cytokinesis is the highly regulated process that physically separates daughter and mother cells in late mitosis. The mitotic-exit network (MEN), the signalling pathway that drives mitotic exit, directly regulates cytokinesis. Discover the latest research on mitotic-exit networks with cytokinesis here.

DNA Replication Origin

DNA replication is initiated as specific gene sequences, called origins, that function to start DNA replication. Pre-replication complexes are assembled at these origins during the G1 phase of the cell cycle. These sequences allow for targeted activation or deactivation of replication. Discover the latest research on DNA replication origins here.