2-Introduction_to_embryology_2024W1__1_

Lesson 1: Learning Outcomes

• Course objectives, learning tools, and assessments

• Ken’s office hours and contact information

• Anatomical directional terms overview

• Predictions on developmental disruptions during:

  • Cleavage

  • Blastula formation (including epiblast and hypoblast in chicks)

  • Gastrulation

  • Neurulation

General Course Objectives

• Compare anatomy and embryonic origins of organ systems across vertebrate taxa

• Evaluate the classification of an unidentified vertebrate based on anatomical and physiological information

• Analyze the impact of anatomical differences on structure function

Instructors

• Lab Instructor: Dr. Tyler Donner

  • Email: tyler.donner@ubc.ca

  • Office Location: By appointment in Arts and Sciences Centre 293

• Lecture Instructor: Dr. Ken Savage

  • Email: ken.savage@ubc.ca

  • Office Location: SCI 161

  • Office Hours: TBD

• Lecture Schedule: Mondays/Wednesdays, 8:00 – 9:20 am in EME 0050

Texts and Materials

• Vertebrates: Comparative Anatomy, Function, Evolution (by Kenneth V. Kardong)

  • Optional, available at the bookstore

• iClicker: required for participation and feedback in lectures

Evaluation Breakdown

• Lecture: 70% of the total mark

  • 5% for Clicker Questions / Participation

  • 25% for Lecture Midterm Exam (scheduled for Oct. 19th; 80 minutes, in-class)

  • 40% for Final Exam

• Lab: 30% of the total mark

• Course syllabus and lab manual contain additional details

Learning Tools

• For Lecture Material:

  • In-class Clicker Questions

  • End-of-unit Study Questions

• For Lab Material:

  • Pre-reading assignments

  • Lab discussion questions and worksheets

Vertebrate Symmetry

• Vertebrates exhibit bilateral symmetry

• Key Terms:

  • Midline: divides body into left and right

Prokaryotes vs Eukaryotes

• Differentiation based on genetic sequences: e.g., 18s rRNA

• Prokaryotes (Bacteria and Archaea)

• Eukaryotes (genetic similarities and differences)

Features of Prokaryotes and Eukaryotes

• Prokaryotes: No nucleus, circular DNA

• Eukaryotes: DNA associated with histones, internal membranes

Carl Woese and Molecular Phylogenies

• Developed the Three-Domain Hypothesis: Bacteria, Archaea, Eukarya

• Discussed concepts of monophyletic and synapomorphic traits in this framework

Comparative Physiology and Evolution

• Importance of functional trade-offs in relation to environmental forces (aquatic vs terrestrial)

• Krogh Principle: Identifying optimal organisms for studying specific biological issues

Anatomical Vocabulary

• Directional Terms: Dorsal, Ventral, Anterior, Posterior, Medial, Lateral, Distal, Proximal

• Distinctions between terms:

  • Medial: toward the midline

  • Lateral: toward the side

  • Proximal: closer to limb attachment

  • Distal: farther from limb attachment

Embryonic Development and Germ Layers

• All vertebrates begin as a single fertilized egg that undergoes cleavage

• Key stages:

  • Cleavage, Blastula Formation, Gastrulation, Neurulation

• Three embryonic germ layers:

  • Ectoderm, Mesoderm, Endoderm

Consequences of Disruption in Developmental Stages

• Effects of deficiencies (e.g. folic acid) on crucial structures such as the neural tube

  • Potential issues included improper closure and subsequent risks to survival

Extraembryonic Membranes and Their Functions

• Amnion, Chorion, Allantois:

  • Protect and support embryonic development in amniotes

• Functions include:

  1. Protecting against environmental stress

  2. Gas exchange through chorioallantoic membrane

  3. Nutrient exchange and waste storage via the yolk sac,

Development Problems and Exam Preparation

• Example questions explore knowledge of embryonic structures and potential consequences of developmental failures

• Importance of understanding the fate of embryonic structures in adult vertebrates and principle functions of each germ layer in development.